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  98. <li><a class="reference internal" href="#"><code class="xref py py-mod docutils literal notranslate"><span class="pre">test</span></code> — Regression tests package for Python</a><ul>

  99. <li><a class="reference internal" href="#writing-unit-tests-for-the-test-package">Writing Unit Tests for the <code class="xref py py-mod docutils literal notranslate"><span class="pre">test</span></code> package</a></li>

  100. <li><a class="reference internal" href="#module-test.regrtest">Running tests using the command-line interface</a></li>

  101. </ul>

  102. </li>

  103. <li><a class="reference internal" href="#module-test.support"><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support</span></code> — Utilities for the Python test suite</a></li>

  104. <li><a class="reference internal" href="#module-test.support.socket_helper"><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.socket_helper</span></code> — Utilities for socket tests</a></li>

  105. <li><a class="reference internal" href="#module-test.support.script_helper"><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.script_helper</span></code> — Utilities for the Python execution tests</a></li>

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  107. <li><a class="reference internal" href="#module-test.support.threading_helper"><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.threading_helper</span></code> — Utilities for threading tests</a></li>

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  201.   <section id="module-test">

  202. <span id="test-regression-tests-package-for-python"></span><h1><a class="reference internal" href="#module-test" title="test: Regression tests package containing the testing suite for Python."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test</span></code></a> — Regression tests package for Python<a class="headerlink" href="#module-test" title="Link to this heading">¶</a></h1>

  203. <div class="admonition note">

  204. <p class="admonition-title">Note</p>

  205. <p>The <a class="reference internal" href="#module-test" title="test: Regression tests package containing the testing suite for Python."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test</span></code></a> package is meant for internal use by Python only. It is

  206. documented for the benefit of the core developers of Python. Any use of

  207. this package outside of Python’s standard library is discouraged as code

  208. mentioned here can change or be removed without notice between releases of

  209. Python.</p>

  210. </div>

  211. <hr class="docutils" />

  212. <p>The <a class="reference internal" href="#module-test" title="test: Regression tests package containing the testing suite for Python."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test</span></code></a> package contains all regression tests for Python as well as the

  213. modules <a class="reference internal" href="#module-test.support" title="test.support: Support for Python's regression test suite."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support</span></code></a> and <a class="reference internal" href="#module-test.regrtest" title="test.regrtest: Drives the regression test suite."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.regrtest</span></code></a>.

  214. <a class="reference internal" href="#module-test.support" title="test.support: Support for Python's regression test suite."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support</span></code></a> is used to enhance your tests while

  215. <a class="reference internal" href="#module-test.regrtest" title="test.regrtest: Drives the regression test suite."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.regrtest</span></code></a> drives the testing suite.</p>

  216. <p>Each module in the <a class="reference internal" href="#module-test" title="test: Regression tests package containing the testing suite for Python."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test</span></code></a> package whose name starts with <code class="docutils literal notranslate"><span class="pre">test_</span></code> is a

  217. testing suite for a specific module or feature. All new tests should be written

  218. using the <a class="reference internal" href="unittest.html#module-unittest" title="unittest: Unit testing framework for Python."><code class="xref py py-mod docutils literal notranslate"><span class="pre">unittest</span></code></a> or <a class="reference internal" href="doctest.html#module-doctest" title="doctest: Test pieces of code within docstrings."><code class="xref py py-mod docutils literal notranslate"><span class="pre">doctest</span></code></a> module.  Some older tests are

  219. written using a “traditional” testing style that compares output printed to

  220. <code class="docutils literal notranslate"><span class="pre">sys.stdout</span></code>; this style of test is considered deprecated.</p>

  221. <div class="admonition seealso">

  222. <p class="admonition-title">See also</p>

  223. <dl class="simple">

  224. <dt>Module <a class="reference internal" href="unittest.html#module-unittest" title="unittest: Unit testing framework for Python."><code class="xref py py-mod docutils literal notranslate"><span class="pre">unittest</span></code></a></dt><dd><p>Writing PyUnit regression tests.</p>

  225. </dd>

  226. <dt>Module <a class="reference internal" href="doctest.html#module-doctest" title="doctest: Test pieces of code within docstrings."><code class="xref py py-mod docutils literal notranslate"><span class="pre">doctest</span></code></a></dt><dd><p>Tests embedded in documentation strings.</p>

  227. </dd>

  228. </dl>

  229. </div>

  230. <section id="writing-unit-tests-for-the-test-package">

  231. <span id="writing-tests"></span><h2>Writing Unit Tests for the <a class="reference internal" href="#module-test" title="test: Regression tests package containing the testing suite for Python."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test</span></code></a> package<a class="headerlink" href="#writing-unit-tests-for-the-test-package" title="Link to this heading">¶</a></h2>

  232. <p>It is preferred that tests that use the <a class="reference internal" href="unittest.html#module-unittest" title="unittest: Unit testing framework for Python."><code class="xref py py-mod docutils literal notranslate"><span class="pre">unittest</span></code></a> module follow a few

  233. guidelines. One is to name the test module by starting it with <code class="docutils literal notranslate"><span class="pre">test_</span></code> and end

  234. it with the name of the module being tested. The test methods in the test module

  235. should start with <code class="docutils literal notranslate"><span class="pre">test_</span></code> and end with a description of what the method is

  236. testing. This is needed so that the methods are recognized by the test driver as

  237. test methods. Also, no documentation string for the method should be included. A

  238. comment (such as <code class="docutils literal notranslate"><span class="pre">#</span> <span class="pre">Tests</span> <span class="pre">function</span> <span class="pre">returns</span> <span class="pre">only</span> <span class="pre">True</span> <span class="pre">or</span> <span class="pre">False</span></code>) should be used

  239. to provide documentation for test methods. This is done because documentation

  240. strings get printed out if they exist and thus what test is being run is not

  241. stated.</p>

  242. <p>A basic boilerplate is often used:</p>

  243. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">unittest</span>

  244. <span class="kn">from</span> <span class="nn">test</span> <span class="kn">import</span> <span class="n">support</span>

  245. 

  246. <span class="k">class</span> <span class="nc">MyTestCase1</span><span class="p">(</span><span class="n">unittest</span><span class="o">.</span><span class="n">TestCase</span><span class="p">):</span>

  247. 

  248.     <span class="c1"># Only use setUp() and tearDown() if necessary</span>

  249. 

  250.     <span class="k">def</span> <span class="nf">setUp</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>

  251.         <span class="o">...</span> <span class="n">code</span> <span class="n">to</span> <span class="n">execute</span> <span class="ow">in</span> <span class="n">preparation</span> <span class="k">for</span> <span class="n">tests</span> <span class="o">...</span>

  252. 

  253.     <span class="k">def</span> <span class="nf">tearDown</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>

  254.         <span class="o">...</span> <span class="n">code</span> <span class="n">to</span> <span class="n">execute</span> <span class="n">to</span> <span class="n">clean</span> <span class="n">up</span> <span class="n">after</span> <span class="n">tests</span> <span class="o">...</span>

  255. 

  256.     <span class="k">def</span> <span class="nf">test_feature_one</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>

  257.         <span class="c1"># Test feature one.</span>

  258.         <span class="o">...</span> <span class="n">testing</span> <span class="n">code</span> <span class="o">...</span>

  259. 

  260.     <span class="k">def</span> <span class="nf">test_feature_two</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>

  261.         <span class="c1"># Test feature two.</span>

  262.         <span class="o">...</span> <span class="n">testing</span> <span class="n">code</span> <span class="o">...</span>

  263. 

  264.     <span class="o">...</span> <span class="n">more</span> <span class="n">test</span> <span class="n">methods</span> <span class="o">...</span>

  265. 

  266. <span class="k">class</span> <span class="nc">MyTestCase2</span><span class="p">(</span><span class="n">unittest</span><span class="o">.</span><span class="n">TestCase</span><span class="p">):</span>

  267.     <span class="o">...</span> <span class="n">same</span> <span class="n">structure</span> <span class="k">as</span> <span class="n">MyTestCase1</span> <span class="o">...</span>

  268. 

  269. <span class="o">...</span> <span class="n">more</span> <span class="n">test</span> <span class="n">classes</span> <span class="o">...</span>

  270. 

  271. <span class="k">if</span> <span class="vm">__name__</span> <span class="o">==</span> <span class="s1">&#39;__main__&#39;</span><span class="p">:</span>

  272.     <span class="n">unittest</span><span class="o">.</span><span class="n">main</span><span class="p">()</span>

  273. </pre></div>

  274. </div>

  275. <p>This code pattern allows the testing suite to be run by <a class="reference internal" href="#module-test.regrtest" title="test.regrtest: Drives the regression test suite."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.regrtest</span></code></a>,

  276. on its own as a script that supports the <a class="reference internal" href="unittest.html#module-unittest" title="unittest: Unit testing framework for Python."><code class="xref py py-mod docutils literal notranslate"><span class="pre">unittest</span></code></a> CLI, or via the

  277. <code class="docutils literal notranslate"><span class="pre">python</span> <span class="pre">-m</span> <span class="pre">unittest</span></code> CLI.</p>

  278. <p>The goal for regression testing is to try to break code. This leads to a few

  279. guidelines to be followed:</p>

  280. <ul>

  281. <li><p>The testing suite should exercise all classes, functions, and constants. This

  282. includes not just the external API that is to be presented to the outside

  283. world but also “private” code.</p></li>

  284. <li><p>Whitebox testing (examining the code being tested when the tests are being

  285. written) is preferred. Blackbox testing (testing only the published user

  286. interface) is not complete enough to make sure all boundary and edge cases

  287. are tested.</p></li>

  288. <li><p>Make sure all possible values are tested including invalid ones. This makes

  289. sure that not only all valid values are acceptable but also that improper

  290. values are handled correctly.</p></li>

  291. <li><p>Exhaust as many code paths as possible. Test where branching occurs and thus

  292. tailor input to make sure as many different paths through the code are taken.</p></li>

  293. <li><p>Add an explicit test for any bugs discovered for the tested code. This will

  294. make sure that the error does not crop up again if the code is changed in the

  295. future.</p></li>

  296. <li><p>Make sure to clean up after your tests (such as close and remove all temporary

  297. files).</p></li>

  298. <li><p>If a test is dependent on a specific condition of the operating system then

  299. verify the condition already exists before attempting the test.</p></li>

  300. <li><p>Import as few modules as possible and do it as soon as possible. This

  301. minimizes external dependencies of tests and also minimizes possible anomalous

  302. behavior from side-effects of importing a module.</p></li>

  303. <li><p>Try to maximize code reuse. On occasion, tests will vary by something as small

  304. as what type of input is used. Minimize code duplication by subclassing a

  305. basic test class with a class that specifies the input:</p>

  306. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="k">class</span> <span class="nc">TestFuncAcceptsSequencesMixin</span><span class="p">:</span>

  307. 

  308.     <span class="n">func</span> <span class="o">=</span> <span class="n">mySuperWhammyFunction</span>

  309. 

  310.     <span class="k">def</span> <span class="nf">test_func</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>

  311.         <span class="bp">self</span><span class="o">.</span><span class="n">func</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">arg</span><span class="p">)</span>

  312. 

  313. <span class="k">class</span> <span class="nc">AcceptLists</span><span class="p">(</span><span class="n">TestFuncAcceptsSequencesMixin</span><span class="p">,</span> <span class="n">unittest</span><span class="o">.</span><span class="n">TestCase</span><span class="p">):</span>

  314.     <span class="n">arg</span> <span class="o">=</span> <span class="p">[</span><span class="mi">1</span><span class="p">,</span> <span class="mi">2</span><span class="p">,</span> <span class="mi">3</span><span class="p">]</span>

  315. 

  316. <span class="k">class</span> <span class="nc">AcceptStrings</span><span class="p">(</span><span class="n">TestFuncAcceptsSequencesMixin</span><span class="p">,</span> <span class="n">unittest</span><span class="o">.</span><span class="n">TestCase</span><span class="p">):</span>

  317.     <span class="n">arg</span> <span class="o">=</span> <span class="s1">&#39;abc&#39;</span>

  318. 

  319. <span class="k">class</span> <span class="nc">AcceptTuples</span><span class="p">(</span><span class="n">TestFuncAcceptsSequencesMixin</span><span class="p">,</span> <span class="n">unittest</span><span class="o">.</span><span class="n">TestCase</span><span class="p">):</span>

  320.     <span class="n">arg</span> <span class="o">=</span> <span class="p">(</span><span class="mi">1</span><span class="p">,</span> <span class="mi">2</span><span class="p">,</span> <span class="mi">3</span><span class="p">)</span>

  321. </pre></div>

  322. </div>

  323. <p>When using this pattern, remember that all classes that inherit from

  324. <a class="reference internal" href="unittest.html#unittest.TestCase" title="unittest.TestCase"><code class="xref py py-class docutils literal notranslate"><span class="pre">unittest.TestCase</span></code></a> are run as tests.  The <code class="xref py py-class docutils literal notranslate"><span class="pre">TestFuncAcceptsSequencesMixin</span></code> class in the example above

  325. does not have any data and so can’t be run by itself, thus it does not

  326. inherit from <a class="reference internal" href="unittest.html#unittest.TestCase" title="unittest.TestCase"><code class="xref py py-class docutils literal notranslate"><span class="pre">unittest.TestCase</span></code></a>.</p>

  327. </li>

  328. </ul>

  329. <div class="admonition seealso">

  330. <p class="admonition-title">See also</p>

  331. <dl class="simple">

  332. <dt>Test Driven Development</dt><dd><p>A book by Kent Beck on writing tests before code.</p>

  333. </dd>

  334. </dl>

  335. </div>

  336. </section>

  337. <section id="module-test.regrtest">

  338. <span id="running-tests-using-the-command-line-interface"></span><span id="regrtest"></span><h2>Running tests using the command-line interface<a class="headerlink" href="#module-test.regrtest" title="Link to this heading">¶</a></h2>

  339. <p>The <a class="reference internal" href="#module-test" title="test: Regression tests package containing the testing suite for Python."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test</span></code></a> package can be run as a script to drive Python’s regression

  340. test suite, thanks to the <a class="reference internal" href="../using/cmdline.html#cmdoption-m"><code class="xref std std-option docutils literal notranslate"><span class="pre">-m</span></code></a> option: <strong class="program">python -m test</strong>. Under

  341. the hood, it uses <a class="reference internal" href="#module-test.regrtest" title="test.regrtest: Drives the regression test suite."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.regrtest</span></code></a>; the call <strong class="program">python -m

  342. test.regrtest</strong> used in previous Python versions still works.  Running the

  343. script by itself automatically starts running all regression tests in the

  344. <a class="reference internal" href="#module-test" title="test: Regression tests package containing the testing suite for Python."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test</span></code></a> package. It does this by finding all modules in the package whose

  345. name starts with <code class="docutils literal notranslate"><span class="pre">test_</span></code>, importing them, and executing the function

  346. <code class="xref py py-func docutils literal notranslate"><span class="pre">test_main()</span></code> if present or loading the tests via

  347. unittest.TestLoader.loadTestsFromModule if <code class="docutils literal notranslate"><span class="pre">test_main</span></code> does not exist.  The

  348. names of tests to execute may also be passed to the script. Specifying a single

  349. regression test (<strong class="program">python -m test test_spam</strong>) will minimize output and

  350. only print whether the test passed or failed.</p>

  351. <p>Running <a class="reference internal" href="#module-test" title="test: Regression tests package containing the testing suite for Python."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test</span></code></a> directly allows what resources are available for

  352. tests to use to be set. You do this by using the <code class="docutils literal notranslate"><span class="pre">-u</span></code> command-line

  353. option. Specifying <code class="docutils literal notranslate"><span class="pre">all</span></code> as the value for the <code class="docutils literal notranslate"><span class="pre">-u</span></code> option enables all

  354. possible resources: <strong class="program">python -m test -uall</strong>.

  355. If all but one resource is desired (a more common case), a

  356. comma-separated list of resources that are not desired may be listed after

  357. <code class="docutils literal notranslate"><span class="pre">all</span></code>. The command <strong class="program">python -m test -uall,-audio,-largefile</strong>

  358. will run <a class="reference internal" href="#module-test" title="test: Regression tests package containing the testing suite for Python."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test</span></code></a> with all resources except the <code class="docutils literal notranslate"><span class="pre">audio</span></code> and

  359. <code class="docutils literal notranslate"><span class="pre">largefile</span></code> resources. For a list of all resources and more command-line

  360. options, run <strong class="program">python -m test -h</strong>.</p>

  361. <p>Some other ways to execute the regression tests depend on what platform the

  362. tests are being executed on. On Unix, you can run <strong class="program">make test</strong> at the

  363. top-level directory where Python was built. On Windows,

  364. executing <strong class="program">rt.bat</strong> from your <code class="file docutils literal notranslate"><span class="pre">PCbuild</span></code> directory will run all

  365. regression tests.</p>

  366. </section>

  367. </section>

  368. <section id="module-test.support">

  369. <span id="test-support-utilities-for-the-python-test-suite"></span><h1><a class="reference internal" href="#module-test.support" title="test.support: Support for Python's regression test suite."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support</span></code></a> — Utilities for the Python test suite<a class="headerlink" href="#module-test.support" title="Link to this heading">¶</a></h1>

  370. <p>The <a class="reference internal" href="#module-test.support" title="test.support: Support for Python's regression test suite."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support</span></code></a> module provides support for Python’s regression

  371. test suite.</p>

  372. <div class="admonition note">

  373. <p class="admonition-title">Note</p>

  374. <p><a class="reference internal" href="#module-test.support" title="test.support: Support for Python's regression test suite."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support</span></code></a> is not a public module.  It is documented here to help

  375. Python developers write tests.  The API of this module is subject to change

  376. without backwards compatibility concerns between releases.</p>

  377. </div>

  378. <p>This module defines the following exceptions:</p>

  379. <dl class="py exception">

  380. <dt class="sig sig-object py" id="test.support.TestFailed">

  381. <em class="property"><span class="pre">exception</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">TestFailed</span></span><a class="headerlink" href="#test.support.TestFailed" title="Link to this definition">¶</a></dt>

  382. <dd><p>Exception to be raised when a test fails. This is deprecated in favor of

  383. <a class="reference internal" href="unittest.html#module-unittest" title="unittest: Unit testing framework for Python."><code class="xref py py-mod docutils literal notranslate"><span class="pre">unittest</span></code></a>-based tests and <a class="reference internal" href="unittest.html#unittest.TestCase" title="unittest.TestCase"><code class="xref py py-class docutils literal notranslate"><span class="pre">unittest.TestCase</span></code></a>’s assertion

  384. methods.</p>

  385. </dd></dl>

  386. 

  387. <dl class="py exception">

  388. <dt class="sig sig-object py" id="test.support.ResourceDenied">

  389. <em class="property"><span class="pre">exception</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">ResourceDenied</span></span><a class="headerlink" href="#test.support.ResourceDenied" title="Link to this definition">¶</a></dt>

  390. <dd><p>Subclass of <a class="reference internal" href="unittest.html#unittest.SkipTest" title="unittest.SkipTest"><code class="xref py py-exc docutils literal notranslate"><span class="pre">unittest.SkipTest</span></code></a>. Raised when a resource (such as a

  391. network connection) is not available. Raised by the <a class="reference internal" href="#test.support.requires" title="test.support.requires"><code class="xref py py-func docutils literal notranslate"><span class="pre">requires()</span></code></a>

  392. function.</p>

  393. </dd></dl>

  394. 

  395. <p>The <a class="reference internal" href="#module-test.support" title="test.support: Support for Python's regression test suite."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support</span></code></a> module defines the following constants:</p>

  396. <dl class="py data">

  397. <dt class="sig sig-object py" id="test.support.verbose">

  398. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">verbose</span></span><a class="headerlink" href="#test.support.verbose" title="Link to this definition">¶</a></dt>

  399. <dd><p><code class="docutils literal notranslate"><span class="pre">True</span></code> when verbose output is enabled. Should be checked when more

  400. detailed information is desired about a running test. <em>verbose</em> is set by

  401. <a class="reference internal" href="#module-test.regrtest" title="test.regrtest: Drives the regression test suite."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.regrtest</span></code></a>.</p>

  402. </dd></dl>

  403. 

  404. <dl class="py data">

  405. <dt class="sig sig-object py" id="test.support.is_jython">

  406. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">is_jython</span></span><a class="headerlink" href="#test.support.is_jython" title="Link to this definition">¶</a></dt>

  407. <dd><p><code class="docutils literal notranslate"><span class="pre">True</span></code> if the running interpreter is Jython.</p>

  408. </dd></dl>

  409. 

  410. <dl class="py data">

  411. <dt class="sig sig-object py" id="test.support.is_android">

  412. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">is_android</span></span><a class="headerlink" href="#test.support.is_android" title="Link to this definition">¶</a></dt>

  413. <dd><p><code class="docutils literal notranslate"><span class="pre">True</span></code> if the system is Android.</p>

  414. </dd></dl>

  415. 

  416. <dl class="py data">

  417. <dt class="sig sig-object py" id="test.support.unix_shell">

  418. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">unix_shell</span></span><a class="headerlink" href="#test.support.unix_shell" title="Link to this definition">¶</a></dt>

  419. <dd><p>Path for shell if not on Windows; otherwise <code class="docutils literal notranslate"><span class="pre">None</span></code>.</p>

  420. </dd></dl>

  421. 

  422. <dl class="py data">

  423. <dt class="sig sig-object py" id="test.support.LOOPBACK_TIMEOUT">

  424. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">LOOPBACK_TIMEOUT</span></span><a class="headerlink" href="#test.support.LOOPBACK_TIMEOUT" title="Link to this definition">¶</a></dt>

  425. <dd><p>Timeout in seconds for tests using a network server listening on the network

  426. local loopback interface like <code class="docutils literal notranslate"><span class="pre">127.0.0.1</span></code>.</p>

  427. <p>The timeout is long enough to prevent test failure: it takes into account

  428. that the client and the server can run in different threads or even

  429. different processes.</p>

  430. <p>The timeout should be long enough for <a class="reference internal" href="socket.html#socket.socket.connect" title="socket.socket.connect"><code class="xref py py-meth docutils literal notranslate"><span class="pre">connect()</span></code></a>,

  431. <a class="reference internal" href="socket.html#socket.socket.recv" title="socket.socket.recv"><code class="xref py py-meth docutils literal notranslate"><span class="pre">recv()</span></code></a> and <a class="reference internal" href="socket.html#socket.socket.send" title="socket.socket.send"><code class="xref py py-meth docutils literal notranslate"><span class="pre">send()</span></code></a> methods of

  432. <a class="reference internal" href="socket.html#socket.socket" title="socket.socket"><code class="xref py py-class docutils literal notranslate"><span class="pre">socket.socket</span></code></a>.</p>

  433. <p>Its default value is 5 seconds.</p>

  434. <p>See also <a class="reference internal" href="#test.support.INTERNET_TIMEOUT" title="test.support.INTERNET_TIMEOUT"><code class="xref py py-data docutils literal notranslate"><span class="pre">INTERNET_TIMEOUT</span></code></a>.</p>

  435. </dd></dl>

  436. 

  437. <dl class="py data">

  438. <dt class="sig sig-object py" id="test.support.INTERNET_TIMEOUT">

  439. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">INTERNET_TIMEOUT</span></span><a class="headerlink" href="#test.support.INTERNET_TIMEOUT" title="Link to this definition">¶</a></dt>

  440. <dd><p>Timeout in seconds for network requests going to the internet.</p>

  441. <p>The timeout is short enough to prevent a test to wait for too long if the

  442. internet request is blocked for whatever reason.</p>

  443. <p>Usually, a timeout using <a class="reference internal" href="#test.support.INTERNET_TIMEOUT" title="test.support.INTERNET_TIMEOUT"><code class="xref py py-data docutils literal notranslate"><span class="pre">INTERNET_TIMEOUT</span></code></a> should not mark a test as

  444. failed, but skip the test instead: see

  445. <a class="reference internal" href="#test.support.socket_helper.transient_internet" title="test.support.socket_helper.transient_internet"><code class="xref py py-func docutils literal notranslate"><span class="pre">transient_internet()</span></code></a>.</p>

  446. <p>Its default value is 1 minute.</p>

  447. <p>See also <a class="reference internal" href="#test.support.LOOPBACK_TIMEOUT" title="test.support.LOOPBACK_TIMEOUT"><code class="xref py py-data docutils literal notranslate"><span class="pre">LOOPBACK_TIMEOUT</span></code></a>.</p>

  448. </dd></dl>

  449. 

  450. <dl class="py data">

  451. <dt class="sig sig-object py" id="test.support.SHORT_TIMEOUT">

  452. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">SHORT_TIMEOUT</span></span><a class="headerlink" href="#test.support.SHORT_TIMEOUT" title="Link to this definition">¶</a></dt>

  453. <dd><p>Timeout in seconds to mark a test as failed if the test takes “too long”.</p>

  454. <p>The timeout value depends on the regrtest <code class="docutils literal notranslate"><span class="pre">--timeout</span></code> command line option.</p>

  455. <p>If a test using <a class="reference internal" href="#test.support.SHORT_TIMEOUT" title="test.support.SHORT_TIMEOUT"><code class="xref py py-data docutils literal notranslate"><span class="pre">SHORT_TIMEOUT</span></code></a> starts to fail randomly on slow

  456. buildbots, use <a class="reference internal" href="#test.support.LONG_TIMEOUT" title="test.support.LONG_TIMEOUT"><code class="xref py py-data docutils literal notranslate"><span class="pre">LONG_TIMEOUT</span></code></a> instead.</p>

  457. <p>Its default value is 30 seconds.</p>

  458. </dd></dl>

  459. 

  460. <dl class="py data">

  461. <dt class="sig sig-object py" id="test.support.LONG_TIMEOUT">

  462. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">LONG_TIMEOUT</span></span><a class="headerlink" href="#test.support.LONG_TIMEOUT" title="Link to this definition">¶</a></dt>

  463. <dd><p>Timeout in seconds to detect when a test hangs.</p>

  464. <p>It is long enough to reduce the risk of test failure on the slowest Python

  465. buildbots. It should not be used to mark a test as failed if the test takes

  466. “too long”.  The timeout value depends on the regrtest <code class="docutils literal notranslate"><span class="pre">--timeout</span></code> command

  467. line option.</p>

  468. <p>Its default value is 5 minutes.</p>

  469. <p>See also <a class="reference internal" href="#test.support.LOOPBACK_TIMEOUT" title="test.support.LOOPBACK_TIMEOUT"><code class="xref py py-data docutils literal notranslate"><span class="pre">LOOPBACK_TIMEOUT</span></code></a>, <a class="reference internal" href="#test.support.INTERNET_TIMEOUT" title="test.support.INTERNET_TIMEOUT"><code class="xref py py-data docutils literal notranslate"><span class="pre">INTERNET_TIMEOUT</span></code></a> and

  470. <a class="reference internal" href="#test.support.SHORT_TIMEOUT" title="test.support.SHORT_TIMEOUT"><code class="xref py py-data docutils literal notranslate"><span class="pre">SHORT_TIMEOUT</span></code></a>.</p>

  471. </dd></dl>

  472. 

  473. <dl class="py data">

  474. <dt class="sig sig-object py" id="test.support.PGO">

  475. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">PGO</span></span><a class="headerlink" href="#test.support.PGO" title="Link to this definition">¶</a></dt>

  476. <dd><p>Set when tests can be skipped when they are not useful for PGO.</p>

  477. </dd></dl>

  478. 

  479. <dl class="py data">

  480. <dt class="sig sig-object py" id="test.support.PIPE_MAX_SIZE">

  481. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">PIPE_MAX_SIZE</span></span><a class="headerlink" href="#test.support.PIPE_MAX_SIZE" title="Link to this definition">¶</a></dt>

  482. <dd><p>A constant that is likely larger than the underlying OS pipe buffer size,

  483. to make writes blocking.</p>

  484. </dd></dl>

  485. 

  486. <dl class="py data">

  487. <dt class="sig sig-object py" id="test.support.Py_DEBUG">

  488. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">Py_DEBUG</span></span><a class="headerlink" href="#test.support.Py_DEBUG" title="Link to this definition">¶</a></dt>

  489. <dd><p>True if Python was built with the <a class="reference internal" href="../c-api/intro.html#c.Py_DEBUG" title="Py_DEBUG"><code class="xref c c-macro docutils literal notranslate"><span class="pre">Py_DEBUG</span></code></a> macro

  490. defined, that is, if

  491. Python was <a class="reference internal" href="../using/configure.html#debug-build"><span class="std std-ref">built in debug mode</span></a>.</p>

  492. <div class="versionadded">

  493. <p><span class="versionmodified added">New in version 3.12.</span></p>

  494. </div>

  495. </dd></dl>

  496. 

  497. <dl class="py data">

  498. <dt class="sig sig-object py" id="test.support.SOCK_MAX_SIZE">

  499. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">SOCK_MAX_SIZE</span></span><a class="headerlink" href="#test.support.SOCK_MAX_SIZE" title="Link to this definition">¶</a></dt>

  500. <dd><p>A constant that is likely larger than the underlying OS socket buffer size,

  501. to make writes blocking.</p>

  502. </dd></dl>

  503. 

  504. <dl class="py data">

  505. <dt class="sig sig-object py" id="test.support.TEST_SUPPORT_DIR">

  506. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">TEST_SUPPORT_DIR</span></span><a class="headerlink" href="#test.support.TEST_SUPPORT_DIR" title="Link to this definition">¶</a></dt>

  507. <dd><p>Set to the top level directory that contains <a class="reference internal" href="#module-test.support" title="test.support: Support for Python's regression test suite."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support</span></code></a>.</p>

  508. </dd></dl>

  509. 

  510. <dl class="py data">

  511. <dt class="sig sig-object py" id="test.support.TEST_HOME_DIR">

  512. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">TEST_HOME_DIR</span></span><a class="headerlink" href="#test.support.TEST_HOME_DIR" title="Link to this definition">¶</a></dt>

  513. <dd><p>Set to the top level directory for the test package.</p>

  514. </dd></dl>

  515. 

  516. <dl class="py data">

  517. <dt class="sig sig-object py" id="test.support.TEST_DATA_DIR">

  518. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">TEST_DATA_DIR</span></span><a class="headerlink" href="#test.support.TEST_DATA_DIR" title="Link to this definition">¶</a></dt>

  519. <dd><p>Set to the <code class="docutils literal notranslate"><span class="pre">data</span></code> directory within the test package.</p>

  520. </dd></dl>

  521. 

  522. <dl class="py data">

  523. <dt class="sig sig-object py" id="test.support.MAX_Py_ssize_t">

  524. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">MAX_Py_ssize_t</span></span><a class="headerlink" href="#test.support.MAX_Py_ssize_t" title="Link to this definition">¶</a></dt>

  525. <dd><p>Set to <a class="reference internal" href="sys.html#sys.maxsize" title="sys.maxsize"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.maxsize</span></code></a> for big memory tests.</p>

  526. </dd></dl>

  527. 

  528. <dl class="py data">

  529. <dt class="sig sig-object py" id="test.support.max_memuse">

  530. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">max_memuse</span></span><a class="headerlink" href="#test.support.max_memuse" title="Link to this definition">¶</a></dt>

  531. <dd><p>Set by <a class="reference internal" href="#test.support.set_memlimit" title="test.support.set_memlimit"><code class="xref py py-func docutils literal notranslate"><span class="pre">set_memlimit()</span></code></a> as the memory limit for big memory tests.

  532. Limited by <a class="reference internal" href="#test.support.MAX_Py_ssize_t" title="test.support.MAX_Py_ssize_t"><code class="xref py py-data docutils literal notranslate"><span class="pre">MAX_Py_ssize_t</span></code></a>.</p>

  533. </dd></dl>

  534. 

  535. <dl class="py data">

  536. <dt class="sig sig-object py" id="test.support.real_max_memuse">

  537. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">real_max_memuse</span></span><a class="headerlink" href="#test.support.real_max_memuse" title="Link to this definition">¶</a></dt>

  538. <dd><p>Set by <a class="reference internal" href="#test.support.set_memlimit" title="test.support.set_memlimit"><code class="xref py py-func docutils literal notranslate"><span class="pre">set_memlimit()</span></code></a> as the memory limit for big memory tests.  Not

  539. limited by <a class="reference internal" href="#test.support.MAX_Py_ssize_t" title="test.support.MAX_Py_ssize_t"><code class="xref py py-data docutils literal notranslate"><span class="pre">MAX_Py_ssize_t</span></code></a>.</p>

  540. </dd></dl>

  541. 

  542. <dl class="py data">

  543. <dt class="sig sig-object py" id="test.support.MISSING_C_DOCSTRINGS">

  544. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">MISSING_C_DOCSTRINGS</span></span><a class="headerlink" href="#test.support.MISSING_C_DOCSTRINGS" title="Link to this definition">¶</a></dt>

  545. <dd><p>Set to <code class="docutils literal notranslate"><span class="pre">True</span></code> if Python is built without docstrings (the

  546. <code class="xref c c-macro docutils literal notranslate"><span class="pre">WITH_DOC_STRINGS</span></code> macro is not defined).

  547. See the <a class="reference internal" href="../using/configure.html#cmdoption-without-doc-strings"><code class="xref std std-option docutils literal notranslate"><span class="pre">configure</span> <span class="pre">--without-doc-strings</span></code></a> option.</p>

  548. <p>See also the <a class="reference internal" href="#test.support.HAVE_DOCSTRINGS" title="test.support.HAVE_DOCSTRINGS"><code class="xref py py-data docutils literal notranslate"><span class="pre">HAVE_DOCSTRINGS</span></code></a> variable.</p>

  549. </dd></dl>

  550. 

  551. <dl class="py data">

  552. <dt class="sig sig-object py" id="test.support.HAVE_DOCSTRINGS">

  553. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">HAVE_DOCSTRINGS</span></span><a class="headerlink" href="#test.support.HAVE_DOCSTRINGS" title="Link to this definition">¶</a></dt>

  554. <dd><p>Set to <code class="docutils literal notranslate"><span class="pre">True</span></code> if function docstrings are available.

  555. See the <a class="reference internal" href="../using/cmdline.html#cmdoption-O"><code class="xref std std-option docutils literal notranslate"><span class="pre">python</span> <span class="pre">-OO</span></code></a> option, which strips docstrings of functions implemented in Python.</p>

  556. <p>See also the <a class="reference internal" href="#test.support.MISSING_C_DOCSTRINGS" title="test.support.MISSING_C_DOCSTRINGS"><code class="xref py py-data docutils literal notranslate"><span class="pre">MISSING_C_DOCSTRINGS</span></code></a> variable.</p>

  557. </dd></dl>

  558. 

  559. <dl class="py data">

  560. <dt class="sig sig-object py" id="test.support.TEST_HTTP_URL">

  561. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">TEST_HTTP_URL</span></span><a class="headerlink" href="#test.support.TEST_HTTP_URL" title="Link to this definition">¶</a></dt>

  562. <dd><p>Define the URL of a dedicated HTTP server for the network tests.</p>

  563. </dd></dl>

  564. 

  565. <dl class="py data">

  566. <dt class="sig sig-object py" id="test.support.ALWAYS_EQ">

  567. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">ALWAYS_EQ</span></span><a class="headerlink" href="#test.support.ALWAYS_EQ" title="Link to this definition">¶</a></dt>

  568. <dd><p>Object that is equal to anything.  Used to test mixed type comparison.</p>

  569. </dd></dl>

  570. 

  571. <dl class="py data">

  572. <dt class="sig sig-object py" id="test.support.NEVER_EQ">

  573. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">NEVER_EQ</span></span><a class="headerlink" href="#test.support.NEVER_EQ" title="Link to this definition">¶</a></dt>

  574. <dd><p>Object that is not equal to anything (even to <a class="reference internal" href="#test.support.ALWAYS_EQ" title="test.support.ALWAYS_EQ"><code class="xref py py-data docutils literal notranslate"><span class="pre">ALWAYS_EQ</span></code></a>).

  575. Used to test mixed type comparison.</p>

  576. </dd></dl>

  577. 

  578. <dl class="py data">

  579. <dt class="sig sig-object py" id="test.support.LARGEST">

  580. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">LARGEST</span></span><a class="headerlink" href="#test.support.LARGEST" title="Link to this definition">¶</a></dt>

  581. <dd><p>Object that is greater than anything (except itself).

  582. Used to test mixed type comparison.</p>

  583. </dd></dl>

  584. 

  585. <dl class="py data">

  586. <dt class="sig sig-object py" id="test.support.SMALLEST">

  587. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">SMALLEST</span></span><a class="headerlink" href="#test.support.SMALLEST" title="Link to this definition">¶</a></dt>

  588. <dd><p>Object that is less than anything (except itself).

  589. Used to test mixed type comparison.</p>

  590. </dd></dl>

  591. 

  592. <p>The <a class="reference internal" href="#module-test.support" title="test.support: Support for Python's regression test suite."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support</span></code></a> module defines the following functions:</p>

  593. <dl class="py function">

  594. <dt class="sig sig-object py" id="test.support.busy_retry">

  595. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">busy_retry</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">timeout</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">err_msg</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">/</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">*</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">error</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">True</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.busy_retry" title="Link to this definition">¶</a></dt>

  596. <dd><p>Run the loop body until <code class="docutils literal notranslate"><span class="pre">break</span></code> stops the loop.</p>

  597. <p>After <em>timeout</em> seconds, raise an <a class="reference internal" href="exceptions.html#AssertionError" title="AssertionError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">AssertionError</span></code></a> if <em>error</em> is true,

  598. or just stop the loop if <em>error</em> is false.</p>

  599. <p>Example:</p>

  600. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="k">for</span> <span class="n">_</span> <span class="ow">in</span> <span class="n">support</span><span class="o">.</span><span class="n">busy_retry</span><span class="p">(</span><span class="n">support</span><span class="o">.</span><span class="n">SHORT_TIMEOUT</span><span class="p">):</span>

  601.     <span class="k">if</span> <span class="n">check</span><span class="p">():</span>

  602.         <span class="k">break</span>

  603. </pre></div>

  604. </div>

  605. <p>Example of error=False usage:</p>

  606. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="k">for</span> <span class="n">_</span> <span class="ow">in</span> <span class="n">support</span><span class="o">.</span><span class="n">busy_retry</span><span class="p">(</span><span class="n">support</span><span class="o">.</span><span class="n">SHORT_TIMEOUT</span><span class="p">,</span> <span class="n">error</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span>

  607.     <span class="k">if</span> <span class="n">check</span><span class="p">():</span>

  608.         <span class="k">break</span>

  609. <span class="k">else</span><span class="p">:</span>

  610.     <span class="k">raise</span> <span class="ne">RuntimeError</span><span class="p">(</span><span class="s1">&#39;my custom error&#39;</span><span class="p">)</span>

  611. </pre></div>

  612. </div>

  613. </dd></dl>

  614. 

  615. <dl class="py function">

  616. <dt class="sig sig-object py" id="test.support.sleeping_retry">

  617. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">sleeping_retry</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">timeout</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">err_msg</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">/</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">*</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">init_delay</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">0.010</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">max_delay</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">1.0</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">error</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">True</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.sleeping_retry" title="Link to this definition">¶</a></dt>

  618. <dd><p>Wait strategy that applies exponential backoff.</p>

  619. <p>Run the loop body until <code class="docutils literal notranslate"><span class="pre">break</span></code> stops the loop. Sleep at each loop

  620. iteration, but not at the first iteration. The sleep delay is doubled at

  621. each iteration (up to <em>max_delay</em> seconds).</p>

  622. <p>See <a class="reference internal" href="#test.support.busy_retry" title="test.support.busy_retry"><code class="xref py py-func docutils literal notranslate"><span class="pre">busy_retry()</span></code></a> documentation for the parameters usage.</p>

  623. <p>Example raising an exception after SHORT_TIMEOUT seconds:</p>

  624. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="k">for</span> <span class="n">_</span> <span class="ow">in</span> <span class="n">support</span><span class="o">.</span><span class="n">sleeping_retry</span><span class="p">(</span><span class="n">support</span><span class="o">.</span><span class="n">SHORT_TIMEOUT</span><span class="p">):</span>

  625.     <span class="k">if</span> <span class="n">check</span><span class="p">():</span>

  626.         <span class="k">break</span>

  627. </pre></div>

  628. </div>

  629. <p>Example of error=False usage:</p>

  630. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="k">for</span> <span class="n">_</span> <span class="ow">in</span> <span class="n">support</span><span class="o">.</span><span class="n">sleeping_retry</span><span class="p">(</span><span class="n">support</span><span class="o">.</span><span class="n">SHORT_TIMEOUT</span><span class="p">,</span> <span class="n">error</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span>

  631.     <span class="k">if</span> <span class="n">check</span><span class="p">():</span>

  632.         <span class="k">break</span>

  633. <span class="k">else</span><span class="p">:</span>

  634.     <span class="k">raise</span> <span class="ne">RuntimeError</span><span class="p">(</span><span class="s1">&#39;my custom error&#39;</span><span class="p">)</span>

  635. </pre></div>

  636. </div>

  637. </dd></dl>

  638. 

  639. <dl class="py function">

  640. <dt class="sig sig-object py" id="test.support.is_resource_enabled">

  641. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">is_resource_enabled</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">resource</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.is_resource_enabled" title="Link to this definition">¶</a></dt>

  642. <dd><p>Return <code class="docutils literal notranslate"><span class="pre">True</span></code> if <em>resource</em> is enabled and available. The list of

  643. available resources is only set when <a class="reference internal" href="#module-test.regrtest" title="test.regrtest: Drives the regression test suite."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.regrtest</span></code></a> is executing the

  644. tests.</p>

  645. </dd></dl>

  646. 

  647. <dl class="py function">

  648. <dt class="sig sig-object py" id="test.support.python_is_optimized">

  649. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">python_is_optimized</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.python_is_optimized" title="Link to this definition">¶</a></dt>

  650. <dd><p>Return <code class="docutils literal notranslate"><span class="pre">True</span></code> if Python was not built with <code class="docutils literal notranslate"><span class="pre">-O0</span></code> or <code class="docutils literal notranslate"><span class="pre">-Og</span></code>.</p>

  651. </dd></dl>

  652. 

  653. <dl class="py function">

  654. <dt class="sig sig-object py" id="test.support.with_pymalloc">

  655. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">with_pymalloc</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.with_pymalloc" title="Link to this definition">¶</a></dt>

  656. <dd><p>Return <code class="xref py py-const docutils literal notranslate"><span class="pre">_testcapi.WITH_PYMALLOC</span></code>.</p>

  657. </dd></dl>

  658. 

  659. <dl class="py function">

  660. <dt class="sig sig-object py" id="test.support.requires">

  661. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">requires</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">resource</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">msg</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.requires" title="Link to this definition">¶</a></dt>

  662. <dd><p>Raise <a class="reference internal" href="#test.support.ResourceDenied" title="test.support.ResourceDenied"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ResourceDenied</span></code></a> if <em>resource</em> is not available. <em>msg</em> is the

  663. argument to <a class="reference internal" href="#test.support.ResourceDenied" title="test.support.ResourceDenied"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ResourceDenied</span></code></a> if it is raised. Always returns

  664. <code class="docutils literal notranslate"><span class="pre">True</span></code> if called by a function whose <code class="docutils literal notranslate"><span class="pre">__name__</span></code> is <code class="docutils literal notranslate"><span class="pre">'__main__'</span></code>.

  665. Used when tests are executed by <a class="reference internal" href="#module-test.regrtest" title="test.regrtest: Drives the regression test suite."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.regrtest</span></code></a>.</p>

  666. </dd></dl>

  667. 

  668. <dl class="py function">

  669. <dt class="sig sig-object py" id="test.support.sortdict">

  670. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">sortdict</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">dict</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.sortdict" title="Link to this definition">¶</a></dt>

  671. <dd><p>Return a repr of <em>dict</em> with keys sorted.</p>

  672. </dd></dl>

  673. 

  674. <dl class="py function">

  675. <dt class="sig sig-object py" id="test.support.findfile">

  676. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">findfile</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">filename</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">subdir</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.findfile" title="Link to this definition">¶</a></dt>

  677. <dd><p>Return the path to the file named <em>filename</em>. If no match is found

  678. <em>filename</em> is returned. This does not equal a failure since it could be the

  679. path to the file.</p>

  680. <p>Setting <em>subdir</em> indicates a relative path to use to find the file

  681. rather than looking directly in the path directories.</p>

  682. </dd></dl>

  683. 

  684. <dl class="py function">

  685. <dt class="sig sig-object py" id="test.support.get_pagesize">

  686. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">get_pagesize</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.get_pagesize" title="Link to this definition">¶</a></dt>

  687. <dd><p>Get size of a page in bytes.</p>

  688. <div class="versionadded">

  689. <p><span class="versionmodified added">New in version 3.12.</span></p>

  690. </div>

  691. </dd></dl>

  692. 

  693. <dl class="py function">

  694. <dt class="sig sig-object py" id="test.support.setswitchinterval">

  695. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">setswitchinterval</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">interval</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.setswitchinterval" title="Link to this definition">¶</a></dt>

  696. <dd><p>Set the <a class="reference internal" href="sys.html#sys.setswitchinterval" title="sys.setswitchinterval"><code class="xref py py-func docutils literal notranslate"><span class="pre">sys.setswitchinterval()</span></code></a> to the given <em>interval</em>.  Defines

  697. a minimum interval for Android systems to prevent the system from hanging.</p>

  698. </dd></dl>

  699. 

  700. <dl class="py function">

  701. <dt class="sig sig-object py" id="test.support.check_impl_detail">

  702. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">check_impl_detail</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="o"><span class="pre">**</span></span><span class="n"><span class="pre">guards</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.check_impl_detail" title="Link to this definition">¶</a></dt>

  703. <dd><p>Use this check to guard CPython’s implementation-specific tests or to

  704. run them only on the implementations guarded by the arguments.  This

  705. function returns <code class="docutils literal notranslate"><span class="pre">True</span></code> or <code class="docutils literal notranslate"><span class="pre">False</span></code> depending on the host platform.

  706. Example usage:</p>

  707. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="n">check_impl_detail</span><span class="p">()</span>               <span class="c1"># Only on CPython (default).</span>

  708. <span class="n">check_impl_detail</span><span class="p">(</span><span class="n">jython</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>    <span class="c1"># Only on Jython.</span>

  709. <span class="n">check_impl_detail</span><span class="p">(</span><span class="n">cpython</span><span class="o">=</span><span class="kc">False</span><span class="p">)</span>  <span class="c1"># Everywhere except CPython.</span>

  710. </pre></div>

  711. </div>

  712. </dd></dl>

  713. 

  714. <dl class="py function">

  715. <dt class="sig sig-object py" id="test.support.set_memlimit">

  716. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">set_memlimit</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">limit</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.set_memlimit" title="Link to this definition">¶</a></dt>

  717. <dd><p>Set the values for <a class="reference internal" href="#test.support.max_memuse" title="test.support.max_memuse"><code class="xref py py-data docutils literal notranslate"><span class="pre">max_memuse</span></code></a> and <a class="reference internal" href="#test.support.real_max_memuse" title="test.support.real_max_memuse"><code class="xref py py-data docutils literal notranslate"><span class="pre">real_max_memuse</span></code></a> for big

  718. memory tests.</p>

  719. </dd></dl>

  720. 

  721. <dl class="py function">

  722. <dt class="sig sig-object py" id="test.support.record_original_stdout">

  723. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">record_original_stdout</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">stdout</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.record_original_stdout" title="Link to this definition">¶</a></dt>

  724. <dd><p>Store the value from <em>stdout</em>.  It is meant to hold the stdout at the

  725. time the regrtest began.</p>

  726. </dd></dl>

  727. 

  728. <dl class="py function">

  729. <dt class="sig sig-object py" id="test.support.get_original_stdout">

  730. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">get_original_stdout</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.get_original_stdout" title="Link to this definition">¶</a></dt>

  731. <dd><p>Return the original stdout set by <a class="reference internal" href="#test.support.record_original_stdout" title="test.support.record_original_stdout"><code class="xref py py-func docutils literal notranslate"><span class="pre">record_original_stdout()</span></code></a> or

  732. <code class="docutils literal notranslate"><span class="pre">sys.stdout</span></code> if it’s not set.</p>

  733. </dd></dl>

  734. 

  735. <dl class="py function">

  736. <dt class="sig sig-object py" id="test.support.args_from_interpreter_flags">

  737. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">args_from_interpreter_flags</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.args_from_interpreter_flags" title="Link to this definition">¶</a></dt>

  738. <dd><p>Return a list of command line arguments reproducing the current settings

  739. in <code class="docutils literal notranslate"><span class="pre">sys.flags</span></code> and <code class="docutils literal notranslate"><span class="pre">sys.warnoptions</span></code>.</p>

  740. </dd></dl>

  741. 

  742. <dl class="py function">

  743. <dt class="sig sig-object py" id="test.support.optim_args_from_interpreter_flags">

  744. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">optim_args_from_interpreter_flags</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.optim_args_from_interpreter_flags" title="Link to this definition">¶</a></dt>

  745. <dd><p>Return a list of command line arguments reproducing the current

  746. optimization settings in <code class="docutils literal notranslate"><span class="pre">sys.flags</span></code>.</p>

  747. </dd></dl>

  748. 

  749. <dl class="py function">

  750. <dt class="sig sig-object py" id="test.support.captured_stdin">

  751. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">captured_stdin</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.captured_stdin" title="Link to this definition">¶</a></dt>

  752. <dt class="sig sig-object py" id="test.support.captured_stdout">

  753. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">captured_stdout</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.captured_stdout" title="Link to this definition">¶</a></dt>

  754. <dt class="sig sig-object py" id="test.support.captured_stderr">

  755. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">captured_stderr</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.captured_stderr" title="Link to this definition">¶</a></dt>

  756. <dd><p>A context managers that temporarily replaces the named stream with

  757. <a class="reference internal" href="io.html#io.StringIO" title="io.StringIO"><code class="xref py py-class docutils literal notranslate"><span class="pre">io.StringIO</span></code></a> object.</p>

  758. <p>Example use with output streams:</p>

  759. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="k">with</span> <span class="n">captured_stdout</span><span class="p">()</span> <span class="k">as</span> <span class="n">stdout</span><span class="p">,</span> <span class="n">captured_stderr</span><span class="p">()</span> <span class="k">as</span> <span class="n">stderr</span><span class="p">:</span>

  760.     <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;hello&quot;</span><span class="p">)</span>

  761.     <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;error&quot;</span><span class="p">,</span> <span class="n">file</span><span class="o">=</span><span class="n">sys</span><span class="o">.</span><span class="n">stderr</span><span class="p">)</span>

  762. <span class="k">assert</span> <span class="n">stdout</span><span class="o">.</span><span class="n">getvalue</span><span class="p">()</span> <span class="o">==</span> <span class="s2">&quot;hello</span><span class="se">\n</span><span class="s2">&quot;</span>

  763. <span class="k">assert</span> <span class="n">stderr</span><span class="o">.</span><span class="n">getvalue</span><span class="p">()</span> <span class="o">==</span> <span class="s2">&quot;error</span><span class="se">\n</span><span class="s2">&quot;</span>

  764. </pre></div>

  765. </div>

  766. <p>Example use with input stream:</p>

  767. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="k">with</span> <span class="n">captured_stdin</span><span class="p">()</span> <span class="k">as</span> <span class="n">stdin</span><span class="p">:</span>

  768.     <span class="n">stdin</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="s1">&#39;hello</span><span class="se">\n</span><span class="s1">&#39;</span><span class="p">)</span>

  769.     <span class="n">stdin</span><span class="o">.</span><span class="n">seek</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>

  770.     <span class="c1"># call test code that consumes from sys.stdin</span>

  771.     <span class="n">captured</span> <span class="o">=</span> <span class="nb">input</span><span class="p">()</span>

  772. <span class="bp">self</span><span class="o">.</span><span class="n">assertEqual</span><span class="p">(</span><span class="n">captured</span><span class="p">,</span> <span class="s2">&quot;hello&quot;</span><span class="p">)</span>

  773. </pre></div>

  774. </div>

  775. </dd></dl>

  776. 

  777. <dl class="py function">

  778. <dt class="sig sig-object py" id="test.support.disable_faulthandler">

  779. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">disable_faulthandler</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.disable_faulthandler" title="Link to this definition">¶</a></dt>

  780. <dd><p>A context manager that temporary disables <a class="reference internal" href="faulthandler.html#module-faulthandler" title="faulthandler: Dump the Python traceback."><code class="xref py py-mod docutils literal notranslate"><span class="pre">faulthandler</span></code></a>.</p>

  781. </dd></dl>

  782. 

  783. <dl class="py function">

  784. <dt class="sig sig-object py" id="test.support.gc_collect">

  785. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">gc_collect</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.gc_collect" title="Link to this definition">¶</a></dt>

  786. <dd><p>Force as many objects as possible to be collected.  This is needed because

  787. timely deallocation is not guaranteed by the garbage collector.  This means

  788. that <code class="docutils literal notranslate"><span class="pre">__del__</span></code> methods may be called later than expected and weakrefs

  789. may remain alive for longer than expected.</p>

  790. </dd></dl>

  791. 

  792. <dl class="py function">

  793. <dt class="sig sig-object py" id="test.support.disable_gc">

  794. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">disable_gc</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.disable_gc" title="Link to this definition">¶</a></dt>

  795. <dd><p>A context manager that disables the garbage collector on entry. On

  796. exit, the garbage collector is restored to its prior state.</p>

  797. </dd></dl>

  798. 

  799. <dl class="py function">

  800. <dt class="sig sig-object py" id="test.support.swap_attr">

  801. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">swap_attr</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">obj</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">attr</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">new_val</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.swap_attr" title="Link to this definition">¶</a></dt>

  802. <dd><p>Context manager to swap out an attribute with a new object.</p>

  803. <p>Usage:</p>

  804. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="k">with</span> <span class="n">swap_attr</span><span class="p">(</span><span class="n">obj</span><span class="p">,</span> <span class="s2">&quot;attr&quot;</span><span class="p">,</span> <span class="mi">5</span><span class="p">):</span>

  805.     <span class="o">...</span>

  806. </pre></div>

  807. </div>

  808. <p>This will set <code class="docutils literal notranslate"><span class="pre">obj.attr</span></code> to 5 for the duration of the <code class="docutils literal notranslate"><span class="pre">with</span></code> block,

  809. restoring the old value at the end of the block.  If <code class="docutils literal notranslate"><span class="pre">attr</span></code> doesn’t

  810. exist on <code class="docutils literal notranslate"><span class="pre">obj</span></code>, it will be created and then deleted at the end of the

  811. block.</p>

  812. <p>The old value (or <code class="docutils literal notranslate"><span class="pre">None</span></code> if it doesn’t exist) will be assigned to the

  813. target of the “as” clause, if there is one.</p>

  814. </dd></dl>

  815. 

  816. <dl class="py function">

  817. <dt class="sig sig-object py" id="test.support.swap_item">

  818. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">swap_item</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">obj</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">attr</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">new_val</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.swap_item" title="Link to this definition">¶</a></dt>

  819. <dd><p>Context manager to swap out an item with a new object.</p>

  820. <p>Usage:</p>

  821. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="k">with</span> <span class="n">swap_item</span><span class="p">(</span><span class="n">obj</span><span class="p">,</span> <span class="s2">&quot;item&quot;</span><span class="p">,</span> <span class="mi">5</span><span class="p">):</span>

  822.     <span class="o">...</span>

  823. </pre></div>

  824. </div>

  825. <p>This will set <code class="docutils literal notranslate"><span class="pre">obj[&quot;item&quot;]</span></code> to 5 for the duration of the <code class="docutils literal notranslate"><span class="pre">with</span></code> block,

  826. restoring the old value at the end of the block. If <code class="docutils literal notranslate"><span class="pre">item</span></code> doesn’t

  827. exist on <code class="docutils literal notranslate"><span class="pre">obj</span></code>, it will be created and then deleted at the end of the

  828. block.</p>

  829. <p>The old value (or <code class="docutils literal notranslate"><span class="pre">None</span></code> if it doesn’t exist) will be assigned to the

  830. target of the “as” clause, if there is one.</p>

  831. </dd></dl>

  832. 

  833. <dl class="py function">

  834. <dt class="sig sig-object py" id="test.support.flush_std_streams">

  835. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">flush_std_streams</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.flush_std_streams" title="Link to this definition">¶</a></dt>

  836. <dd><p>Call the <code class="docutils literal notranslate"><span class="pre">flush()</span></code> method on <a class="reference internal" href="sys.html#sys.stdout" title="sys.stdout"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.stdout</span></code></a> and then on

  837. <a class="reference internal" href="sys.html#sys.stderr" title="sys.stderr"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.stderr</span></code></a>. It can be used to make sure that the logs order is

  838. consistent before writing into stderr.</p>

  839. <div class="versionadded">

  840. <p><span class="versionmodified added">New in version 3.11.</span></p>

  841. </div>

  842. </dd></dl>

  843. 

  844. <dl class="py function">

  845. <dt class="sig sig-object py" id="test.support.print_warning">

  846. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">print_warning</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">msg</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.print_warning" title="Link to this definition">¶</a></dt>

  847. <dd><p>Print a warning into <a class="reference internal" href="sys.html#sys.__stderr__" title="sys.__stderr__"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.__stderr__</span></code></a>. Format the message as:

  848. <code class="docutils literal notranslate"><span class="pre">f&quot;Warning</span> <span class="pre">--</span> <span class="pre">{msg}&quot;</span></code>. If <em>msg</em> is made of multiple lines, add

  849. <code class="docutils literal notranslate"><span class="pre">&quot;Warning</span> <span class="pre">--</span> <span class="pre">&quot;</span></code> prefix to each line.</p>

  850. <div class="versionadded">

  851. <p><span class="versionmodified added">New in version 3.9.</span></p>

  852. </div>

  853. </dd></dl>

  854. 

  855. <dl class="py function">

  856. <dt class="sig sig-object py" id="test.support.wait_process">

  857. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">wait_process</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">pid</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">*</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">exitcode</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">timeout</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.wait_process" title="Link to this definition">¶</a></dt>

  858. <dd><p>Wait until process <em>pid</em> completes and check that the process exit code is

  859. <em>exitcode</em>.</p>

  860. <p>Raise an <a class="reference internal" href="exceptions.html#AssertionError" title="AssertionError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">AssertionError</span></code></a> if the process exit code is not equal to

  861. <em>exitcode</em>.</p>

  862. <p>If the process runs longer than <em>timeout</em> seconds (<a class="reference internal" href="#test.support.SHORT_TIMEOUT" title="test.support.SHORT_TIMEOUT"><code class="xref py py-data docutils literal notranslate"><span class="pre">SHORT_TIMEOUT</span></code></a> by

  863. default), kill the process and raise an <a class="reference internal" href="exceptions.html#AssertionError" title="AssertionError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">AssertionError</span></code></a>. The timeout

  864. feature is not available on Windows.</p>

  865. <div class="versionadded">

  866. <p><span class="versionmodified added">New in version 3.9.</span></p>

  867. </div>

  868. </dd></dl>

  869. 

  870. <dl class="py function">

  871. <dt class="sig sig-object py" id="test.support.calcobjsize">

  872. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">calcobjsize</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">fmt</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.calcobjsize" title="Link to this definition">¶</a></dt>

  873. <dd><p>Return the size of the <a class="reference internal" href="../c-api/structures.html#c.PyObject" title="PyObject"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyObject</span></code></a> whose structure members are

  874. defined by <em>fmt</em>. The returned value includes the size of the Python object header and alignment.</p>

  875. </dd></dl>

  876. 

  877. <dl class="py function">

  878. <dt class="sig sig-object py" id="test.support.calcvobjsize">

  879. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">calcvobjsize</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">fmt</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.calcvobjsize" title="Link to this definition">¶</a></dt>

  880. <dd><p>Return the size of the <a class="reference internal" href="../c-api/structures.html#c.PyVarObject" title="PyVarObject"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyVarObject</span></code></a> whose structure members are

  881. defined by <em>fmt</em>. The returned value includes the size of the Python object header and alignment.</p>

  882. </dd></dl>

  883. 

  884. <dl class="py function">

  885. <dt class="sig sig-object py" id="test.support.checksizeof">

  886. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">checksizeof</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">test</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">o</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">size</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.checksizeof" title="Link to this definition">¶</a></dt>

  887. <dd><p>For testcase <em>test</em>, assert that the <code class="docutils literal notranslate"><span class="pre">sys.getsizeof</span></code> for <em>o</em> plus the GC

  888. header size equals <em>size</em>.</p>

  889. </dd></dl>

  890. 

  891. <dl class="py function">

  892. <dt class="sig sig-object py" id="test.support.anticipate_failure">

  893. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">anticipate_failure</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">condition</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.anticipate_failure" title="Link to this definition">¶</a></dt>

  894. <dd><p>A decorator to conditionally mark tests with

  895. <a class="reference internal" href="unittest.html#unittest.expectedFailure" title="unittest.expectedFailure"><code class="xref py py-func docutils literal notranslate"><span class="pre">unittest.expectedFailure()</span></code></a>. Any use of this decorator should

  896. have an associated comment identifying the relevant tracker issue.</p>

  897. </dd></dl>

  898. 

  899. <dl class="py function">

  900. <dt class="sig sig-object py" id="test.support.system_must_validate_cert">

  901. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">system_must_validate_cert</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">f</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.system_must_validate_cert" title="Link to this definition">¶</a></dt>

  902. <dd><p>A decorator that skips the decorated test on TLS certification validation failures.</p>

  903. </dd></dl>

  904. 

  905. <dl class="py function">

  906. <dt class="sig sig-object py" id="test.support.run_with_locale">

  907. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">run_with_locale</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">catstr</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">*</span></span><span class="n"><span class="pre">locales</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.run_with_locale" title="Link to this definition">¶</a></dt>

  908. <dd><p>A decorator for running a function in a different locale, correctly

  909. resetting it after it has finished.  <em>catstr</em> is the locale category as

  910. a string (for example <code class="docutils literal notranslate"><span class="pre">&quot;LC_ALL&quot;</span></code>).  The <em>locales</em> passed will be tried

  911. sequentially, and the first valid locale will be used.</p>

  912. </dd></dl>

  913. 

  914. <dl class="py function">

  915. <dt class="sig sig-object py" id="test.support.run_with_tz">

  916. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">run_with_tz</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">tz</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.run_with_tz" title="Link to this definition">¶</a></dt>

  917. <dd><p>A decorator for running a function in a specific timezone, correctly

  918. resetting it after it has finished.</p>

  919. </dd></dl>

  920. 

  921. <dl class="py function">

  922. <dt class="sig sig-object py" id="test.support.requires_freebsd_version">

  923. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">requires_freebsd_version</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="o"><span class="pre">*</span></span><span class="n"><span class="pre">min_version</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.requires_freebsd_version" title="Link to this definition">¶</a></dt>

  924. <dd><p>Decorator for the minimum version when running test on FreeBSD.  If the

  925. FreeBSD version is less than the minimum, the test is skipped.</p>

  926. </dd></dl>

  927. 

  928. <dl class="py function">

  929. <dt class="sig sig-object py" id="test.support.requires_linux_version">

  930. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">requires_linux_version</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="o"><span class="pre">*</span></span><span class="n"><span class="pre">min_version</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.requires_linux_version" title="Link to this definition">¶</a></dt>

  931. <dd><p>Decorator for the minimum version when running test on Linux.  If the

  932. Linux version is less than the minimum, the test is skipped.</p>

  933. </dd></dl>

  934. 

  935. <dl class="py function">

  936. <dt class="sig sig-object py" id="test.support.requires_mac_version">

  937. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">requires_mac_version</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="o"><span class="pre">*</span></span><span class="n"><span class="pre">min_version</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.requires_mac_version" title="Link to this definition">¶</a></dt>

  938. <dd><p>Decorator for the minimum version when running test on macOS.  If the

  939. macOS version is less than the minimum, the test is skipped.</p>

  940. </dd></dl>

  941. 

  942. <dl class="py function">

  943. <dt class="sig sig-object py" id="test.support.requires_IEEE_754">

  944. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">requires_IEEE_754</span></span><a class="headerlink" href="#test.support.requires_IEEE_754" title="Link to this definition">¶</a></dt>

  945. <dd><p>Decorator for skipping tests on non-IEEE 754 platforms.</p>

  946. </dd></dl>

  947. 

  948. <dl class="py function">

  949. <dt class="sig sig-object py" id="test.support.requires_zlib">

  950. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">requires_zlib</span></span><a class="headerlink" href="#test.support.requires_zlib" title="Link to this definition">¶</a></dt>

  951. <dd><p>Decorator for skipping tests if <a class="reference internal" href="zlib.html#module-zlib" title="zlib: Low-level interface to compression and decompression routines compatible with gzip."><code class="xref py py-mod docutils literal notranslate"><span class="pre">zlib</span></code></a> doesn’t exist.</p>

  952. </dd></dl>

  953. 

  954. <dl class="py function">

  955. <dt class="sig sig-object py" id="test.support.requires_gzip">

  956. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">requires_gzip</span></span><a class="headerlink" href="#test.support.requires_gzip" title="Link to this definition">¶</a></dt>

  957. <dd><p>Decorator for skipping tests if <a class="reference internal" href="gzip.html#module-gzip" title="gzip: Interfaces for gzip compression and decompression using file objects."><code class="xref py py-mod docutils literal notranslate"><span class="pre">gzip</span></code></a> doesn’t exist.</p>

  958. </dd></dl>

  959. 

  960. <dl class="py function">

  961. <dt class="sig sig-object py" id="test.support.requires_bz2">

  962. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">requires_bz2</span></span><a class="headerlink" href="#test.support.requires_bz2" title="Link to this definition">¶</a></dt>

  963. <dd><p>Decorator for skipping tests if <a class="reference internal" href="bz2.html#module-bz2" title="bz2: Interfaces for bzip2 compression and decompression."><code class="xref py py-mod docutils literal notranslate"><span class="pre">bz2</span></code></a> doesn’t exist.</p>

  964. </dd></dl>

  965. 

  966. <dl class="py function">

  967. <dt class="sig sig-object py" id="test.support.requires_lzma">

  968. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">requires_lzma</span></span><a class="headerlink" href="#test.support.requires_lzma" title="Link to this definition">¶</a></dt>

  969. <dd><p>Decorator for skipping tests if <a class="reference internal" href="lzma.html#module-lzma" title="lzma: A Python wrapper for the liblzma compression library."><code class="xref py py-mod docutils literal notranslate"><span class="pre">lzma</span></code></a> doesn’t exist.</p>

  970. </dd></dl>

  971. 

  972. <dl class="py function">

  973. <dt class="sig sig-object py" id="test.support.requires_resource">

  974. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">requires_resource</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">resource</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.requires_resource" title="Link to this definition">¶</a></dt>

  975. <dd><p>Decorator for skipping tests if <em>resource</em> is not available.</p>

  976. </dd></dl>

  977. 

  978. <dl class="py function">

  979. <dt class="sig sig-object py" id="test.support.requires_docstrings">

  980. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">requires_docstrings</span></span><a class="headerlink" href="#test.support.requires_docstrings" title="Link to this definition">¶</a></dt>

  981. <dd><p>Decorator for only running the test if <a class="reference internal" href="#test.support.HAVE_DOCSTRINGS" title="test.support.HAVE_DOCSTRINGS"><code class="xref py py-data docutils literal notranslate"><span class="pre">HAVE_DOCSTRINGS</span></code></a>.</p>

  982. </dd></dl>

  983. 

  984. <dl class="py function">

  985. <dt class="sig sig-object py" id="test.support.requires_limited_api">

  986. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">requires_limited_api</span></span><a class="headerlink" href="#test.support.requires_limited_api" title="Link to this definition">¶</a></dt>

  987. <dd><p>Decorator for only running the test if <a class="reference internal" href="../c-api/stable.html#limited-c-api"><span class="std std-ref">Limited C API</span></a>

  988. is available.</p>

  989. </dd></dl>

  990. 

  991. <dl class="py function">

  992. <dt class="sig sig-object py" id="test.support.cpython_only">

  993. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">cpython_only</span></span><a class="headerlink" href="#test.support.cpython_only" title="Link to this definition">¶</a></dt>

  994. <dd><p>Decorator for tests only applicable to CPython.</p>

  995. </dd></dl>

  996. 

  997. <dl class="py function">

  998. <dt class="sig sig-object py" id="test.support.impl_detail">

  999. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">impl_detail</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">msg</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">**</span></span><span class="n"><span class="pre">guards</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.impl_detail" title="Link to this definition">¶</a></dt>

  1000. <dd><p>Decorator for invoking <a class="reference internal" href="#test.support.check_impl_detail" title="test.support.check_impl_detail"><code class="xref py py-func docutils literal notranslate"><span class="pre">check_impl_detail()</span></code></a> on <em>guards</em>.  If that

  1001. returns <code class="docutils literal notranslate"><span class="pre">False</span></code>, then uses <em>msg</em> as the reason for skipping the test.</p>

  1002. </dd></dl>

  1003. 

  1004. <dl class="py function">

  1005. <dt class="sig sig-object py" id="test.support.no_tracing">

  1006. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">no_tracing</span></span><a class="headerlink" href="#test.support.no_tracing" title="Link to this definition">¶</a></dt>

  1007. <dd><p>Decorator to temporarily turn off tracing for the duration of the test.</p>

  1008. </dd></dl>

  1009. 

  1010. <dl class="py function">

  1011. <dt class="sig sig-object py" id="test.support.refcount_test">

  1012. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">refcount_test</span></span><a class="headerlink" href="#test.support.refcount_test" title="Link to this definition">¶</a></dt>

  1013. <dd><p>Decorator for tests which involve reference counting.  The decorator does

  1014. not run the test if it is not run by CPython.  Any trace function is unset

  1015. for the duration of the test to prevent unexpected refcounts caused by

  1016. the trace function.</p>

  1017. </dd></dl>

  1018. 

  1019. <dl class="py function">

  1020. <dt class="sig sig-object py" id="test.support.bigmemtest">

  1021. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">bigmemtest</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">size</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">memuse</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">dry_run</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">True</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.bigmemtest" title="Link to this definition">¶</a></dt>

  1022. <dd><p>Decorator for bigmem tests.</p>

  1023. <p><em>size</em> is a requested size for the test (in arbitrary, test-interpreted

  1024. units.)  <em>memuse</em> is the number of bytes per unit for the test, or a good

  1025. estimate of it.  For example, a test that needs two byte buffers, of 4 GiB

  1026. each, could be decorated with <code class="docutils literal notranslate"><span class="pre">&#64;bigmemtest(size=_4G,</span> <span class="pre">memuse=2)</span></code>.</p>

  1027. <p>The <em>size</em> argument is normally passed to the decorated test method as an

  1028. extra argument.  If <em>dry_run</em> is <code class="docutils literal notranslate"><span class="pre">True</span></code>, the value passed to the test

  1029. method may be less than the requested value.  If <em>dry_run</em> is <code class="docutils literal notranslate"><span class="pre">False</span></code>, it

  1030. means the test doesn’t support dummy runs when <code class="docutils literal notranslate"><span class="pre">-M</span></code> is not specified.</p>

  1031. </dd></dl>

  1032. 

  1033. <dl class="py function">

  1034. <dt class="sig sig-object py" id="test.support.bigaddrspacetest">

  1035. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">bigaddrspacetest</span></span><a class="headerlink" href="#test.support.bigaddrspacetest" title="Link to this definition">¶</a></dt>

  1036. <dd><p>Decorator for tests that fill the address space.</p>

  1037. </dd></dl>

  1038. 

  1039. <dl class="py function">

  1040. <dt class="sig sig-object py" id="test.support.check_syntax_error">

  1041. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">check_syntax_error</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">testcase</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">statement</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">errtext</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">''</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">*</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">lineno</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">offset</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.check_syntax_error" title="Link to this definition">¶</a></dt>

  1042. <dd><p>Test for syntax errors in <em>statement</em> by attempting to compile <em>statement</em>.

  1043. <em>testcase</em> is the <a class="reference internal" href="unittest.html#module-unittest" title="unittest: Unit testing framework for Python."><code class="xref py py-mod docutils literal notranslate"><span class="pre">unittest</span></code></a> instance for the test.  <em>errtext</em> is the

  1044. regular expression which should match the string representation of the

  1045. raised <a class="reference internal" href="exceptions.html#SyntaxError" title="SyntaxError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">SyntaxError</span></code></a>.  If <em>lineno</em> is not <code class="docutils literal notranslate"><span class="pre">None</span></code>, compares to

  1046. the line of the exception.  If <em>offset</em> is not <code class="docutils literal notranslate"><span class="pre">None</span></code>, compares to

  1047. the offset of the exception.</p>

  1048. </dd></dl>

  1049. 

  1050. <dl class="py function">

  1051. <dt class="sig sig-object py" id="test.support.open_urlresource">

  1052. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">open_urlresource</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">url</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">*</span></span><span class="n"><span class="pre">args</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">**</span></span><span class="n"><span class="pre">kw</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.open_urlresource" title="Link to this definition">¶</a></dt>

  1053. <dd><p>Open <em>url</em>.  If open fails, raises <a class="reference internal" href="#test.support.TestFailed" title="test.support.TestFailed"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TestFailed</span></code></a>.</p>

  1054. </dd></dl>

  1055. 

  1056. <dl class="py function">

  1057. <dt class="sig sig-object py" id="test.support.reap_children">

  1058. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">reap_children</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.reap_children" title="Link to this definition">¶</a></dt>

  1059. <dd><p>Use this at the end of <code class="docutils literal notranslate"><span class="pre">test_main</span></code> whenever sub-processes are started.

  1060. This will help ensure that no extra children (zombies) stick around to

  1061. hog resources and create problems when looking for refleaks.</p>

  1062. </dd></dl>

  1063. 

  1064. <dl class="py function">

  1065. <dt class="sig sig-object py" id="test.support.get_attribute">

  1066. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">get_attribute</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">obj</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">name</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.get_attribute" title="Link to this definition">¶</a></dt>

  1067. <dd><p>Get an attribute, raising <a class="reference internal" href="unittest.html#unittest.SkipTest" title="unittest.SkipTest"><code class="xref py py-exc docutils literal notranslate"><span class="pre">unittest.SkipTest</span></code></a> if <a class="reference internal" href="exceptions.html#AttributeError" title="AttributeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">AttributeError</span></code></a>

  1068. is raised.</p>

  1069. </dd></dl>

  1070. 

  1071. <dl class="py function">

  1072. <dt class="sig sig-object py" id="test.support.catch_unraisable_exception">

  1073. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">catch_unraisable_exception</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.catch_unraisable_exception" title="Link to this definition">¶</a></dt>

  1074. <dd><p>Context manager catching unraisable exception using

  1075. <a class="reference internal" href="sys.html#sys.unraisablehook" title="sys.unraisablehook"><code class="xref py py-func docutils literal notranslate"><span class="pre">sys.unraisablehook()</span></code></a>.</p>

  1076. <p>Storing the exception value (<code class="docutils literal notranslate"><span class="pre">cm.unraisable.exc_value</span></code>) creates a

  1077. reference cycle. The reference cycle is broken explicitly when the context

  1078. manager exits.</p>

  1079. <p>Storing the object (<code class="docutils literal notranslate"><span class="pre">cm.unraisable.object</span></code>) can resurrect it if it is set

  1080. to an object which is being finalized. Exiting the context manager clears

  1081. the stored object.</p>

  1082. <p>Usage:</p>

  1083. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="k">with</span> <span class="n">support</span><span class="o">.</span><span class="n">catch_unraisable_exception</span><span class="p">()</span> <span class="k">as</span> <span class="n">cm</span><span class="p">:</span>

  1084.     <span class="c1"># code creating an &quot;unraisable exception&quot;</span>

  1085.     <span class="o">...</span>

  1086. 

  1087.     <span class="c1"># check the unraisable exception: use cm.unraisable</span>

  1088.     <span class="o">...</span>

  1089. 

  1090. <span class="c1"># cm.unraisable attribute no longer exists at this point</span>

  1091. <span class="c1"># (to break a reference cycle)</span>

  1092. </pre></div>

  1093. </div>

  1094. <div class="versionadded">

  1095. <p><span class="versionmodified added">New in version 3.8.</span></p>

  1096. </div>

  1097. </dd></dl>

  1098. 

  1099. <dl class="py function">

  1100. <dt class="sig sig-object py" id="test.support.load_package_tests">

  1101. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">load_package_tests</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">pkg_dir</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">loader</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">standard_tests</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">pattern</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.load_package_tests" title="Link to this definition">¶</a></dt>

  1102. <dd><p>Generic implementation of the <a class="reference internal" href="unittest.html#module-unittest" title="unittest: Unit testing framework for Python."><code class="xref py py-mod docutils literal notranslate"><span class="pre">unittest</span></code></a> <code class="docutils literal notranslate"><span class="pre">load_tests</span></code> protocol for

  1103. use in test packages.  <em>pkg_dir</em> is the root directory of the package;

  1104. <em>loader</em>, <em>standard_tests</em>, and <em>pattern</em> are the arguments expected by

  1105. <code class="docutils literal notranslate"><span class="pre">load_tests</span></code>.  In simple cases, the test package’s <code class="docutils literal notranslate"><span class="pre">__init__.py</span></code>

  1106. can be the following:</p>

  1107. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">os</span>

  1108. <span class="kn">from</span> <span class="nn">test.support</span> <span class="kn">import</span> <span class="n">load_package_tests</span>

  1109. 

  1110. <span class="k">def</span> <span class="nf">load_tests</span><span class="p">(</span><span class="o">*</span><span class="n">args</span><span class="p">):</span>

  1111.     <span class="k">return</span> <span class="n">load_package_tests</span><span class="p">(</span><span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">dirname</span><span class="p">(</span><span class="vm">__file__</span><span class="p">),</span> <span class="o">*</span><span class="n">args</span><span class="p">)</span>

  1112. </pre></div>

  1113. </div>

  1114. </dd></dl>

  1115. 

  1116. <dl class="py function">

  1117. <dt class="sig sig-object py" id="test.support.detect_api_mismatch">

  1118. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">detect_api_mismatch</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">ref_api</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">other_api</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">*</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">ignore</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">()</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.detect_api_mismatch" title="Link to this definition">¶</a></dt>

  1119. <dd><p>Returns the set of attributes, functions or methods of <em>ref_api</em> not

  1120. found on <em>other_api</em>, except for a defined list of items to be

  1121. ignored in this check specified in <em>ignore</em>.</p>

  1122. <p>By default this skips private attributes beginning with ‘_’ but

  1123. includes all magic methods, i.e. those starting and ending in ‘__’.</p>

  1124. <div class="versionadded">

  1125. <p><span class="versionmodified added">New in version 3.5.</span></p>

  1126. </div>

  1127. </dd></dl>

  1128. 

  1129. <dl class="py function">

  1130. <dt class="sig sig-object py" id="test.support.patch">

  1131. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">patch</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">test_instance</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">object_to_patch</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">attr_name</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">new_value</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.patch" title="Link to this definition">¶</a></dt>

  1132. <dd><p>Override <em>object_to_patch.attr_name</em> with <em>new_value</em>.  Also add

  1133. cleanup procedure to <em>test_instance</em> to restore <em>object_to_patch</em> for

  1134. <em>attr_name</em>.  The <em>attr_name</em> should be a valid attribute for

  1135. <em>object_to_patch</em>.</p>

  1136. </dd></dl>

  1137. 

  1138. <dl class="py function">

  1139. <dt class="sig sig-object py" id="test.support.run_in_subinterp">

  1140. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">run_in_subinterp</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">code</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.run_in_subinterp" title="Link to this definition">¶</a></dt>

  1141. <dd><p>Run <em>code</em> in subinterpreter.  Raise <a class="reference internal" href="unittest.html#unittest.SkipTest" title="unittest.SkipTest"><code class="xref py py-exc docutils literal notranslate"><span class="pre">unittest.SkipTest</span></code></a> if

  1142. <a class="reference internal" href="tracemalloc.html#module-tracemalloc" title="tracemalloc: Trace memory allocations."><code class="xref py py-mod docutils literal notranslate"><span class="pre">tracemalloc</span></code></a> is enabled.</p>

  1143. </dd></dl>

  1144. 

  1145. <dl class="py function">

  1146. <dt class="sig sig-object py" id="test.support.check_free_after_iterating">

  1147. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">check_free_after_iterating</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">test</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">iter</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">cls</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">args</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">()</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.check_free_after_iterating" title="Link to this definition">¶</a></dt>

  1148. <dd><p>Assert instances of <em>cls</em> are deallocated after iterating.</p>

  1149. </dd></dl>

  1150. 

  1151. <dl class="py function">

  1152. <dt class="sig sig-object py" id="test.support.missing_compiler_executable">

  1153. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">missing_compiler_executable</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">cmd_names</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">[]</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.missing_compiler_executable" title="Link to this definition">¶</a></dt>

  1154. <dd><p>Check for the existence of the compiler executables whose names are listed

  1155. in <em>cmd_names</em> or all the compiler executables when <em>cmd_names</em> is empty

  1156. and return the first missing executable or <code class="docutils literal notranslate"><span class="pre">None</span></code> when none is found

  1157. missing.</p>

  1158. </dd></dl>

  1159. 

  1160. <dl class="py function">

  1161. <dt class="sig sig-object py" id="test.support.check__all__">

  1162. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">check__all__</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">test_case</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">module</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">name_of_module</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">extra</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">()</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">not_exported</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">()</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.check__all__" title="Link to this definition">¶</a></dt>

  1163. <dd><p>Assert that the <code class="docutils literal notranslate"><span class="pre">__all__</span></code> variable of <em>module</em> contains all public names.</p>

  1164. <p>The module’s public names (its API) are detected automatically

  1165. based on whether they match the public name convention and were defined in

  1166. <em>module</em>.</p>

  1167. <p>The <em>name_of_module</em> argument can specify (as a string or tuple thereof) what

  1168. module(s) an API could be defined in order to be detected as a public

  1169. API. One case for this is when <em>module</em> imports part of its public API from

  1170. other modules, possibly a C backend (like <code class="docutils literal notranslate"><span class="pre">csv</span></code> and its <code class="docutils literal notranslate"><span class="pre">_csv</span></code>).</p>

  1171. <p>The <em>extra</em> argument can be a set of names that wouldn’t otherwise be automatically

  1172. detected as “public”, like objects without a proper <code class="docutils literal notranslate"><span class="pre">__module__</span></code>

  1173. attribute. If provided, it will be added to the automatically detected ones.</p>

  1174. <p>The <em>not_exported</em> argument can be a set of names that must not be treated

  1175. as part of the public API even though their names indicate otherwise.</p>

  1176. <p>Example use:</p>

  1177. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">bar</span>

  1178. <span class="kn">import</span> <span class="nn">foo</span>

  1179. <span class="kn">import</span> <span class="nn">unittest</span>

  1180. <span class="kn">from</span> <span class="nn">test</span> <span class="kn">import</span> <span class="n">support</span>

  1181. 

  1182. <span class="k">class</span> <span class="nc">MiscTestCase</span><span class="p">(</span><span class="n">unittest</span><span class="o">.</span><span class="n">TestCase</span><span class="p">):</span>

  1183.     <span class="k">def</span> <span class="nf">test__all__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>

  1184.         <span class="n">support</span><span class="o">.</span><span class="n">check__all__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">foo</span><span class="p">)</span>

  1185. 

  1186. <span class="k">class</span> <span class="nc">OtherTestCase</span><span class="p">(</span><span class="n">unittest</span><span class="o">.</span><span class="n">TestCase</span><span class="p">):</span>

  1187.     <span class="k">def</span> <span class="nf">test__all__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>

  1188.         <span class="n">extra</span> <span class="o">=</span> <span class="p">{</span><span class="s1">&#39;BAR_CONST&#39;</span><span class="p">,</span> <span class="s1">&#39;FOO_CONST&#39;</span><span class="p">}</span>

  1189.         <span class="n">not_exported</span> <span class="o">=</span> <span class="p">{</span><span class="s1">&#39;baz&#39;</span><span class="p">}</span>  <span class="c1"># Undocumented name.</span>

  1190.         <span class="c1"># bar imports part of its API from _bar.</span>

  1191.         <span class="n">support</span><span class="o">.</span><span class="n">check__all__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">bar</span><span class="p">,</span> <span class="p">(</span><span class="s1">&#39;bar&#39;</span><span class="p">,</span> <span class="s1">&#39;_bar&#39;</span><span class="p">),</span>

  1192.                              <span class="n">extra</span><span class="o">=</span><span class="n">extra</span><span class="p">,</span> <span class="n">not_exported</span><span class="o">=</span><span class="n">not_exported</span><span class="p">)</span>

  1193. </pre></div>

  1194. </div>

  1195. <div class="versionadded">

  1196. <p><span class="versionmodified added">New in version 3.6.</span></p>

  1197. </div>

  1198. </dd></dl>

  1199. 

  1200. <dl class="py function">

  1201. <dt class="sig sig-object py" id="test.support.skip_if_broken_multiprocessing_synchronize">

  1202. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">skip_if_broken_multiprocessing_synchronize</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.skip_if_broken_multiprocessing_synchronize" title="Link to this definition">¶</a></dt>

  1203. <dd><p>Skip tests if the <code class="xref py py-mod docutils literal notranslate"><span class="pre">multiprocessing.synchronize</span></code> module is missing, if

  1204. there is no available semaphore implementation, or if creating a lock raises

  1205. an <a class="reference internal" href="exceptions.html#OSError" title="OSError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">OSError</span></code></a>.</p>

  1206. <div class="versionadded">

  1207. <p><span class="versionmodified added">New in version 3.10.</span></p>

  1208. </div>

  1209. </dd></dl>

  1210. 

  1211. <dl class="py function">

  1212. <dt class="sig sig-object py" id="test.support.check_disallow_instantiation">

  1213. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">check_disallow_instantiation</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">test_case</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">tp</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">*</span></span><span class="n"><span class="pre">args</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">**</span></span><span class="n"><span class="pre">kwds</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.check_disallow_instantiation" title="Link to this definition">¶</a></dt>

  1214. <dd><p>Assert that type <em>tp</em> cannot be instantiated using <em>args</em> and <em>kwds</em>.</p>

  1215. <div class="versionadded">

  1216. <p><span class="versionmodified added">New in version 3.10.</span></p>

  1217. </div>

  1218. </dd></dl>

  1219. 

  1220. <dl class="py function">

  1221. <dt class="sig sig-object py" id="test.support.adjust_int_max_str_digits">

  1222. <span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">adjust_int_max_str_digits</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">max_digits</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.adjust_int_max_str_digits" title="Link to this definition">¶</a></dt>

  1223. <dd><p>This function returns a context manager that will change the global

  1224. <a class="reference internal" href="sys.html#sys.set_int_max_str_digits" title="sys.set_int_max_str_digits"><code class="xref py py-func docutils literal notranslate"><span class="pre">sys.set_int_max_str_digits()</span></code></a> setting for the duration of the

  1225. context to allow execution of test code that needs a different limit

  1226. on the number of digits when converting between an integer and string.</p>

  1227. <div class="versionadded">

  1228. <p><span class="versionmodified added">New in version 3.11.</span></p>

  1229. </div>

  1230. </dd></dl>

  1231. 

  1232. <p>The <a class="reference internal" href="#module-test.support" title="test.support: Support for Python's regression test suite."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support</span></code></a> module defines the following classes:</p>

  1233. <dl class="py class">

  1234. <dt class="sig sig-object py" id="test.support.SuppressCrashReport">

  1235. <em class="property"><span class="pre">class</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">SuppressCrashReport</span></span><a class="headerlink" href="#test.support.SuppressCrashReport" title="Link to this definition">¶</a></dt>

  1236. <dd><p>A context manager used to try to prevent crash dialog popups on tests that

  1237. are expected to crash a subprocess.</p>

  1238. <p>On Windows, it disables Windows Error Reporting dialogs using

  1239. <a class="reference external" href="https://msdn.microsoft.com/en-us/library/windows/desktop/ms680621.aspx">SetErrorMode</a>.</p>

  1240. <p>On UNIX, <a class="reference internal" href="resource.html#resource.setrlimit" title="resource.setrlimit"><code class="xref py py-func docutils literal notranslate"><span class="pre">resource.setrlimit()</span></code></a> is used to set

  1241. <a class="reference internal" href="resource.html#resource.RLIMIT_CORE" title="resource.RLIMIT_CORE"><code class="xref py py-const docutils literal notranslate"><span class="pre">resource.RLIMIT_CORE</span></code></a>’s soft limit to 0 to prevent coredump file

  1242. creation.</p>

  1243. <p>On both platforms, the old value is restored by <a class="reference internal" href="../reference/datamodel.html#object.__exit__" title="object.__exit__"><code class="xref py py-meth docutils literal notranslate"><span class="pre">__exit__()</span></code></a>.</p>

  1244. </dd></dl>

  1245. 

  1246. <dl class="py class">

  1247. <dt class="sig sig-object py" id="test.support.SaveSignals">

  1248. <em class="property"><span class="pre">class</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">SaveSignals</span></span><a class="headerlink" href="#test.support.SaveSignals" title="Link to this definition">¶</a></dt>

  1249. <dd><p>Class to save and restore signal handlers registered by the Python signal

  1250. handler.</p>

  1251. <dl class="py method">

  1252. <dt class="sig sig-object py" id="test.support.SaveSignals.save">

  1253. <span class="sig-name descname"><span class="pre">save</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">self</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.SaveSignals.save" title="Link to this definition">¶</a></dt>

  1254. <dd><p>Save the signal handlers to a dictionary mapping signal numbers to the

  1255. current signal handler.</p>

  1256. </dd></dl>

  1257. 

  1258. <dl class="py method">

  1259. <dt class="sig sig-object py" id="test.support.SaveSignals.restore">

  1260. <span class="sig-name descname"><span class="pre">restore</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">self</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.SaveSignals.restore" title="Link to this definition">¶</a></dt>

  1261. <dd><p>Set the signal numbers from the <a class="reference internal" href="#test.support.SaveSignals.save" title="test.support.SaveSignals.save"><code class="xref py py-meth docutils literal notranslate"><span class="pre">save()</span></code></a> dictionary to the saved

  1262. handler.</p>

  1263. </dd></dl>

  1264. 

  1265. </dd></dl>

  1266. 

  1267. <dl class="py class">

  1268. <dt class="sig sig-object py" id="test.support.Matcher">

  1269. <em class="property"><span class="pre">class</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">test.support.</span></span><span class="sig-name descname"><span class="pre">Matcher</span></span><a class="headerlink" href="#test.support.Matcher" title="Link to this definition">¶</a></dt>

  1270. <dd><dl class="py method">

  1271. <dt class="sig sig-object py" id="test.support.Matcher.matches">

  1272. <span class="sig-name descname"><span class="pre">matches</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">self</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">d</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">**</span></span><span class="n"><span class="pre">kwargs</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.Matcher.matches" title="Link to this definition">¶</a></dt>

  1273. <dd><p>Try to match a single dict with the supplied arguments.</p>

  1274. </dd></dl>

  1275. 

  1276. <dl class="py method">

  1277. <dt class="sig sig-object py" id="test.support.Matcher.match_value">

  1278. <span class="sig-name descname"><span class="pre">match_value</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">self</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">k</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">dv</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">v</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.Matcher.match_value" title="Link to this definition">¶</a></dt>

  1279. <dd><p>Try to match a single stored value (<em>dv</em>) with a supplied value (<em>v</em>).</p>

  1280. </dd></dl>

  1281. 

  1282. </dd></dl>

  1283. 

  1284. </section>

  1285. <section id="module-test.support.socket_helper">

  1286. <span id="test-support-socket-helper-utilities-for-socket-tests"></span><h1><a class="reference internal" href="#module-test.support.socket_helper" title="test.support.socket_helper: Support for socket tests."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.socket_helper</span></code></a> — Utilities for socket tests<a class="headerlink" href="#module-test.support.socket_helper" title="Link to this heading">¶</a></h1>

  1287. <p>The <a class="reference internal" href="#module-test.support.socket_helper" title="test.support.socket_helper: Support for socket tests."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.socket_helper</span></code></a> module provides support for socket tests.</p>

  1288. <div class="versionadded">

  1289. <p><span class="versionmodified added">New in version 3.9.</span></p>

  1290. </div>

  1291. <dl class="py data">

  1292. <dt class="sig sig-object py" id="test.support.socket_helper.IPV6_ENABLED">

  1293. <span class="sig-prename descclassname"><span class="pre">test.support.socket_helper.</span></span><span class="sig-name descname"><span class="pre">IPV6_ENABLED</span></span><a class="headerlink" href="#test.support.socket_helper.IPV6_ENABLED" title="Link to this definition">¶</a></dt>

  1294. <dd><p>Set to <code class="docutils literal notranslate"><span class="pre">True</span></code> if IPv6 is enabled on this host, <code class="docutils literal notranslate"><span class="pre">False</span></code> otherwise.</p>

  1295. </dd></dl>

  1296. 

  1297. <dl class="py function">

  1298. <dt class="sig sig-object py" id="test.support.socket_helper.find_unused_port">

  1299. <span class="sig-prename descclassname"><span class="pre">test.support.socket_helper.</span></span><span class="sig-name descname"><span class="pre">find_unused_port</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">family</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">socket.AF_INET</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">socktype</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">socket.SOCK_STREAM</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.socket_helper.find_unused_port" title="Link to this definition">¶</a></dt>

  1300. <dd><p>Returns an unused port that should be suitable for binding.  This is

  1301. achieved by creating a temporary socket with the same family and type as

  1302. the <code class="docutils literal notranslate"><span class="pre">sock</span></code> parameter (default is <a class="reference internal" href="socket.html#socket.AF_INET" title="socket.AF_INET"><code class="xref py py-const docutils literal notranslate"><span class="pre">AF_INET</span></code></a>,

  1303. <a class="reference internal" href="socket.html#socket.SOCK_STREAM" title="socket.SOCK_STREAM"><code class="xref py py-const docutils literal notranslate"><span class="pre">SOCK_STREAM</span></code></a>),

  1304. and binding it to the specified host address (defaults to <code class="docutils literal notranslate"><span class="pre">0.0.0.0</span></code>)

  1305. with the port set to 0, eliciting an unused ephemeral port from the OS.

  1306. The temporary socket is then closed and deleted, and the ephemeral port is

  1307. returned.</p>

  1308. <p>Either this method or <a class="reference internal" href="#test.support.socket_helper.bind_port" title="test.support.socket_helper.bind_port"><code class="xref py py-func docutils literal notranslate"><span class="pre">bind_port()</span></code></a> should be used for any tests

  1309. where a server socket needs to be bound to a particular port for the

  1310. duration of the test.

  1311. Which one to use depends on whether the calling code is creating a Python

  1312. socket, or if an unused port needs to be provided in a constructor

  1313. or passed to an external program (i.e. the <code class="docutils literal notranslate"><span class="pre">-accept</span></code> argument to

  1314. openssl’s s_server mode).  Always prefer <a class="reference internal" href="#test.support.socket_helper.bind_port" title="test.support.socket_helper.bind_port"><code class="xref py py-func docutils literal notranslate"><span class="pre">bind_port()</span></code></a> over

  1315. <a class="reference internal" href="#test.support.socket_helper.find_unused_port" title="test.support.socket_helper.find_unused_port"><code class="xref py py-func docutils literal notranslate"><span class="pre">find_unused_port()</span></code></a> where possible.  Using a hard coded port is

  1316. discouraged since it can make multiple instances of the test impossible to

  1317. run simultaneously, which is a problem for buildbots.</p>

  1318. </dd></dl>

  1319. 

  1320. <dl class="py function">

  1321. <dt class="sig sig-object py" id="test.support.socket_helper.bind_port">

  1322. <span class="sig-prename descclassname"><span class="pre">test.support.socket_helper.</span></span><span class="sig-name descname"><span class="pre">bind_port</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">sock</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">host</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">HOST</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.socket_helper.bind_port" title="Link to this definition">¶</a></dt>

  1323. <dd><p>Bind the socket to a free port and return the port number.  Relies on

  1324. ephemeral ports in order to ensure we are using an unbound port.  This is

  1325. important as many tests may be running simultaneously, especially in a

  1326. buildbot environment.  This method raises an exception if the

  1327. <code class="docutils literal notranslate"><span class="pre">sock.family</span></code> is <a class="reference internal" href="socket.html#socket.AF_INET" title="socket.AF_INET"><code class="xref py py-const docutils literal notranslate"><span class="pre">AF_INET</span></code></a> and <code class="docutils literal notranslate"><span class="pre">sock.type</span></code> is

  1328. <a class="reference internal" href="socket.html#socket.SOCK_STREAM" title="socket.SOCK_STREAM"><code class="xref py py-const docutils literal notranslate"><span class="pre">SOCK_STREAM</span></code></a>, and the socket has

  1329. <code class="xref py py-const docutils literal notranslate"><span class="pre">SO_REUSEADDR</span></code> or <code class="xref py py-const docutils literal notranslate"><span class="pre">SO_REUSEPORT</span></code> set on it.

  1330. Tests should never set these socket options for TCP/IP sockets.

  1331. The only case for setting these options is testing multicasting via

  1332. multiple UDP sockets.</p>

  1333. <p>Additionally, if the <code class="xref py py-const docutils literal notranslate"><span class="pre">SO_EXCLUSIVEADDRUSE</span></code> socket option is

  1334. available (i.e. on Windows), it will be set on the socket.  This will

  1335. prevent anyone else from binding to our host/port for the duration of the

  1336. test.</p>

  1337. </dd></dl>

  1338. 

  1339. <dl class="py function">

  1340. <dt class="sig sig-object py" id="test.support.socket_helper.bind_unix_socket">

  1341. <span class="sig-prename descclassname"><span class="pre">test.support.socket_helper.</span></span><span class="sig-name descname"><span class="pre">bind_unix_socket</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">sock</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">addr</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.socket_helper.bind_unix_socket" title="Link to this definition">¶</a></dt>

  1342. <dd><p>Bind a Unix socket, raising <a class="reference internal" href="unittest.html#unittest.SkipTest" title="unittest.SkipTest"><code class="xref py py-exc docutils literal notranslate"><span class="pre">unittest.SkipTest</span></code></a> if

  1343. <a class="reference internal" href="exceptions.html#PermissionError" title="PermissionError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">PermissionError</span></code></a> is raised.</p>

  1344. </dd></dl>

  1345. 

  1346. <dl class="py function">

  1347. <dt class="sig sig-object py" id="test.support.socket_helper.skip_unless_bind_unix_socket">

  1348. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.socket_helper.</span></span><span class="sig-name descname"><span class="pre">skip_unless_bind_unix_socket</span></span><a class="headerlink" href="#test.support.socket_helper.skip_unless_bind_unix_socket" title="Link to this definition">¶</a></dt>

  1349. <dd><p>A decorator for running tests that require a functional <code class="docutils literal notranslate"><span class="pre">bind()</span></code> for Unix

  1350. sockets.</p>

  1351. </dd></dl>

  1352. 

  1353. <dl class="py function">

  1354. <dt class="sig sig-object py" id="test.support.socket_helper.transient_internet">

  1355. <span class="sig-prename descclassname"><span class="pre">test.support.socket_helper.</span></span><span class="sig-name descname"><span class="pre">transient_internet</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">resource_name</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">*</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">timeout</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">30.0</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">errnos</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">()</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.socket_helper.transient_internet" title="Link to this definition">¶</a></dt>

  1356. <dd><p>A context manager that raises <a class="reference internal" href="#test.support.ResourceDenied" title="test.support.ResourceDenied"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ResourceDenied</span></code></a> when

  1357. various issues with the internet connection manifest themselves as

  1358. exceptions.</p>

  1359. </dd></dl>

  1360. 

  1361. </section>

  1362. <section id="module-test.support.script_helper">

  1363. <span id="test-support-script-helper-utilities-for-the-python-execution-tests"></span><h1><a class="reference internal" href="#module-test.support.script_helper" title="test.support.script_helper: Support for Python's script execution tests."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.script_helper</span></code></a> — Utilities for the Python execution tests<a class="headerlink" href="#module-test.support.script_helper" title="Link to this heading">¶</a></h1>

  1364. <p>The <a class="reference internal" href="#module-test.support.script_helper" title="test.support.script_helper: Support for Python's script execution tests."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.script_helper</span></code></a> module provides support for Python’s

  1365. script execution tests.</p>

  1366. <dl class="py function">

  1367. <dt class="sig sig-object py" id="test.support.script_helper.interpreter_requires_environment">

  1368. <span class="sig-prename descclassname"><span class="pre">test.support.script_helper.</span></span><span class="sig-name descname"><span class="pre">interpreter_requires_environment</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.script_helper.interpreter_requires_environment" title="Link to this definition">¶</a></dt>

  1369. <dd><p>Return <code class="docutils literal notranslate"><span class="pre">True</span></code> if <code class="docutils literal notranslate"><span class="pre">sys.executable</span> <span class="pre">interpreter</span></code> requires environment

  1370. variables in order to be able to run at all.</p>

  1371. <p>This is designed to be used with <code class="docutils literal notranslate"><span class="pre">&#64;unittest.skipIf()</span></code> to annotate tests

  1372. that need to use an <code class="docutils literal notranslate"><span class="pre">assert_python*()</span></code> function to launch an isolated

  1373. mode (<code class="docutils literal notranslate"><span class="pre">-I</span></code>) or no environment mode (<code class="docutils literal notranslate"><span class="pre">-E</span></code>) sub-interpreter process.</p>

  1374. <p>A normal build &amp; test does not run into this situation but it can happen

  1375. when trying to run the standard library test suite from an interpreter that

  1376. doesn’t have an obvious home with Python’s current home finding logic.</p>

  1377. <p>Setting <span class="target" id="index-0"></span><a class="reference internal" href="../using/cmdline.html#envvar-PYTHONHOME"><code class="xref std std-envvar docutils literal notranslate"><span class="pre">PYTHONHOME</span></code></a> is one way to get most of the testsuite to run

  1378. in that situation.  <span class="target" id="index-1"></span><a class="reference internal" href="../using/cmdline.html#envvar-PYTHONPATH"><code class="xref std std-envvar docutils literal notranslate"><span class="pre">PYTHONPATH</span></code></a> or <span class="target" id="index-2"></span><code class="xref std std-envvar docutils literal notranslate"><span class="pre">PYTHONUSERSITE</span></code> are

  1379. other common environment variables that might impact whether or not the

  1380. interpreter can start.</p>

  1381. </dd></dl>

  1382. 

  1383. <dl class="py function">

  1384. <dt class="sig sig-object py" id="test.support.script_helper.run_python_until_end">

  1385. <span class="sig-prename descclassname"><span class="pre">test.support.script_helper.</span></span><span class="sig-name descname"><span class="pre">run_python_until_end</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="o"><span class="pre">*</span></span><span class="n"><span class="pre">args</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">**</span></span><span class="n"><span class="pre">env_vars</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.script_helper.run_python_until_end" title="Link to this definition">¶</a></dt>

  1386. <dd><p>Set up the environment based on <em>env_vars</em> for running the interpreter

  1387. in a subprocess.  The values can include <code class="docutils literal notranslate"><span class="pre">__isolated</span></code>, <code class="docutils literal notranslate"><span class="pre">__cleanenv</span></code>,

  1388. <code class="docutils literal notranslate"><span class="pre">__cwd</span></code>, and <code class="docutils literal notranslate"><span class="pre">TERM</span></code>.</p>

  1389. <div class="versionchanged">

  1390. <p><span class="versionmodified changed">Changed in version 3.9: </span>The function no longer strips whitespaces from <em>stderr</em>.</p>

  1391. </div>

  1392. </dd></dl>

  1393. 

  1394. <dl class="py function">

  1395. <dt class="sig sig-object py" id="test.support.script_helper.assert_python_ok">

  1396. <span class="sig-prename descclassname"><span class="pre">test.support.script_helper.</span></span><span class="sig-name descname"><span class="pre">assert_python_ok</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="o"><span class="pre">*</span></span><span class="n"><span class="pre">args</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">**</span></span><span class="n"><span class="pre">env_vars</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.script_helper.assert_python_ok" title="Link to this definition">¶</a></dt>

  1397. <dd><p>Assert that running the interpreter with <em>args</em> and optional environment

  1398. variables <em>env_vars</em> succeeds (<code class="docutils literal notranslate"><span class="pre">rc</span> <span class="pre">==</span> <span class="pre">0</span></code>) and return a <code class="docutils literal notranslate"><span class="pre">(return</span> <span class="pre">code,</span>

  1399. <span class="pre">stdout,</span> <span class="pre">stderr)</span></code> tuple.</p>

  1400. <p>If the <em>__cleanenv</em> keyword-only parameter is set, <em>env_vars</em> is used as a fresh

  1401. environment.</p>

  1402. <p>Python is started in isolated mode (command line option <code class="docutils literal notranslate"><span class="pre">-I</span></code>),

  1403. except if the <em>__isolated</em> keyword-only parameter is set to <code class="docutils literal notranslate"><span class="pre">False</span></code>.</p>

  1404. <div class="versionchanged">

  1405. <p><span class="versionmodified changed">Changed in version 3.9: </span>The function no longer strips whitespaces from <em>stderr</em>.</p>

  1406. </div>

  1407. </dd></dl>

  1408. 

  1409. <dl class="py function">

  1410. <dt class="sig sig-object py" id="test.support.script_helper.assert_python_failure">

  1411. <span class="sig-prename descclassname"><span class="pre">test.support.script_helper.</span></span><span class="sig-name descname"><span class="pre">assert_python_failure</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="o"><span class="pre">*</span></span><span class="n"><span class="pre">args</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">**</span></span><span class="n"><span class="pre">env_vars</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.script_helper.assert_python_failure" title="Link to this definition">¶</a></dt>

  1412. <dd><p>Assert that running the interpreter with <em>args</em> and optional environment

  1413. variables <em>env_vars</em> fails (<code class="docutils literal notranslate"><span class="pre">rc</span> <span class="pre">!=</span> <span class="pre">0</span></code>) and return a <code class="docutils literal notranslate"><span class="pre">(return</span> <span class="pre">code,</span>

  1414. <span class="pre">stdout,</span> <span class="pre">stderr)</span></code> tuple.</p>

  1415. <p>See <a class="reference internal" href="#test.support.script_helper.assert_python_ok" title="test.support.script_helper.assert_python_ok"><code class="xref py py-func docutils literal notranslate"><span class="pre">assert_python_ok()</span></code></a> for more options.</p>

  1416. <div class="versionchanged">

  1417. <p><span class="versionmodified changed">Changed in version 3.9: </span>The function no longer strips whitespaces from <em>stderr</em>.</p>

  1418. </div>

  1419. </dd></dl>

  1420. 

  1421. <dl class="py function">

  1422. <dt class="sig sig-object py" id="test.support.script_helper.spawn_python">

  1423. <span class="sig-prename descclassname"><span class="pre">test.support.script_helper.</span></span><span class="sig-name descname"><span class="pre">spawn_python</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="o"><span class="pre">*</span></span><span class="n"><span class="pre">args</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">stdout</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">subprocess.PIPE</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">stderr</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">subprocess.STDOUT</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">**</span></span><span class="n"><span class="pre">kw</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.script_helper.spawn_python" title="Link to this definition">¶</a></dt>

  1424. <dd><p>Run a Python subprocess with the given arguments.</p>

  1425. <p><em>kw</em> is extra keyword args to pass to <a class="reference internal" href="subprocess.html#subprocess.Popen" title="subprocess.Popen"><code class="xref py py-func docutils literal notranslate"><span class="pre">subprocess.Popen()</span></code></a>. Returns a

  1426. <a class="reference internal" href="subprocess.html#subprocess.Popen" title="subprocess.Popen"><code class="xref py py-class docutils literal notranslate"><span class="pre">subprocess.Popen</span></code></a> object.</p>

  1427. </dd></dl>

  1428. 

  1429. <dl class="py function">

  1430. <dt class="sig sig-object py" id="test.support.script_helper.kill_python">

  1431. <span class="sig-prename descclassname"><span class="pre">test.support.script_helper.</span></span><span class="sig-name descname"><span class="pre">kill_python</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">p</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.script_helper.kill_python" title="Link to this definition">¶</a></dt>

  1432. <dd><p>Run the given <a class="reference internal" href="subprocess.html#subprocess.Popen" title="subprocess.Popen"><code class="xref py py-class docutils literal notranslate"><span class="pre">subprocess.Popen</span></code></a> process until completion and return

  1433. stdout.</p>

  1434. </dd></dl>

  1435. 

  1436. <dl class="py function">

  1437. <dt class="sig sig-object py" id="test.support.script_helper.make_script">

  1438. <span class="sig-prename descclassname"><span class="pre">test.support.script_helper.</span></span><span class="sig-name descname"><span class="pre">make_script</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">script_dir</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">script_basename</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">source</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">omit_suffix</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">False</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.script_helper.make_script" title="Link to this definition">¶</a></dt>

  1439. <dd><p>Create script containing <em>source</em> in path <em>script_dir</em> and <em>script_basename</em>.

  1440. If <em>omit_suffix</em> is <code class="docutils literal notranslate"><span class="pre">False</span></code>, append <code class="docutils literal notranslate"><span class="pre">.py</span></code> to the name.  Return the full

  1441. script path.</p>

  1442. </dd></dl>

  1443. 

  1444. <dl class="py function">

  1445. <dt class="sig sig-object py" id="test.support.script_helper.make_zip_script">

  1446. <span class="sig-prename descclassname"><span class="pre">test.support.script_helper.</span></span><span class="sig-name descname"><span class="pre">make_zip_script</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">zip_dir</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">zip_basename</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">script_name</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">name_in_zip</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.script_helper.make_zip_script" title="Link to this definition">¶</a></dt>

  1447. <dd><p>Create zip file at <em>zip_dir</em> and <em>zip_basename</em> with extension <code class="docutils literal notranslate"><span class="pre">zip</span></code> which

  1448. contains the files in <em>script_name</em>. <em>name_in_zip</em> is the archive name.

  1449. Return a tuple containing <code class="docutils literal notranslate"><span class="pre">(full</span> <span class="pre">path,</span> <span class="pre">full</span> <span class="pre">path</span> <span class="pre">of</span> <span class="pre">archive</span> <span class="pre">name)</span></code>.</p>

  1450. </dd></dl>

  1451. 

  1452. <dl class="py function">

  1453. <dt class="sig sig-object py" id="test.support.script_helper.make_pkg">

  1454. <span class="sig-prename descclassname"><span class="pre">test.support.script_helper.</span></span><span class="sig-name descname"><span class="pre">make_pkg</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">pkg_dir</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">init_source</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">''</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.script_helper.make_pkg" title="Link to this definition">¶</a></dt>

  1455. <dd><p>Create a directory named <em>pkg_dir</em> containing an <code class="docutils literal notranslate"><span class="pre">__init__</span></code> file with

  1456. <em>init_source</em> as its contents.</p>

  1457. </dd></dl>

  1458. 

  1459. <dl class="py function">

  1460. <dt class="sig sig-object py" id="test.support.script_helper.make_zip_pkg">

  1461. <span class="sig-prename descclassname"><span class="pre">test.support.script_helper.</span></span><span class="sig-name descname"><span class="pre">make_zip_pkg</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">zip_dir</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">zip_basename</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">pkg_name</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">script_basename</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">source</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">depth</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">1</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">compiled</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">False</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.script_helper.make_zip_pkg" title="Link to this definition">¶</a></dt>

  1462. <dd><p>Create a zip package directory with a path of <em>zip_dir</em> and <em>zip_basename</em>

  1463. containing an empty <code class="docutils literal notranslate"><span class="pre">__init__</span></code> file and a file <em>script_basename</em>

  1464. containing the <em>source</em>.  If <em>compiled</em> is <code class="docutils literal notranslate"><span class="pre">True</span></code>, both source files will

  1465. be compiled and added to the zip package.  Return a tuple of the full zip

  1466. path and the archive name for the zip file.</p>

  1467. </dd></dl>

  1468. 

  1469. </section>

  1470. <section id="module-test.support.bytecode_helper">

  1471. <span id="test-support-bytecode-helper-support-tools-for-testing-correct-bytecode-generation"></span><h1><a class="reference internal" href="#module-test.support.bytecode_helper" title="test.support.bytecode_helper: Support tools for testing correct bytecode generation."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.bytecode_helper</span></code></a> — Support tools for testing correct bytecode generation<a class="headerlink" href="#module-test.support.bytecode_helper" title="Link to this heading">¶</a></h1>

  1472. <p>The <a class="reference internal" href="#module-test.support.bytecode_helper" title="test.support.bytecode_helper: Support tools for testing correct bytecode generation."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.bytecode_helper</span></code></a> module provides support for testing

  1473. and inspecting bytecode generation.</p>

  1474. <div class="versionadded">

  1475. <p><span class="versionmodified added">New in version 3.9.</span></p>

  1476. </div>

  1477. <p>The module defines the following class:</p>

  1478. <dl class="py class">

  1479. <dt class="sig sig-object py" id="test.support.bytecode_helper.BytecodeTestCase">

  1480. <em class="property"><span class="pre">class</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">test.support.bytecode_helper.</span></span><span class="sig-name descname"><span class="pre">BytecodeTestCase</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">unittest.TestCase</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.bytecode_helper.BytecodeTestCase" title="Link to this definition">¶</a></dt>

  1481. <dd><p>This class has custom assertion methods for inspecting bytecode.</p>

  1482. </dd></dl>

  1483. 

  1484. <dl class="py method">

  1485. <dt class="sig sig-object py" id="test.support.bytecode_helper.BytecodeTestCase.get_disassembly_as_string">

  1486. <span class="sig-prename descclassname"><span class="pre">BytecodeTestCase.</span></span><span class="sig-name descname"><span class="pre">get_disassembly_as_string</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">co</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.bytecode_helper.BytecodeTestCase.get_disassembly_as_string" title="Link to this definition">¶</a></dt>

  1487. <dd><p>Return the disassembly of <em>co</em> as string.</p>

  1488. </dd></dl>

  1489. 

  1490. <dl class="py method">

  1491. <dt class="sig sig-object py" id="test.support.bytecode_helper.BytecodeTestCase.assertInBytecode">

  1492. <span class="sig-prename descclassname"><span class="pre">BytecodeTestCase.</span></span><span class="sig-name descname"><span class="pre">assertInBytecode</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">x</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">opname</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">argval</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">_UNSPECIFIED</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.bytecode_helper.BytecodeTestCase.assertInBytecode" title="Link to this definition">¶</a></dt>

  1493. <dd><p>Return instr if <em>opname</em> is found, otherwise throws <a class="reference internal" href="exceptions.html#AssertionError" title="AssertionError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">AssertionError</span></code></a>.</p>

  1494. </dd></dl>

  1495. 

  1496. <dl class="py method">

  1497. <dt class="sig sig-object py" id="test.support.bytecode_helper.BytecodeTestCase.assertNotInBytecode">

  1498. <span class="sig-prename descclassname"><span class="pre">BytecodeTestCase.</span></span><span class="sig-name descname"><span class="pre">assertNotInBytecode</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">x</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">opname</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">argval</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">_UNSPECIFIED</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.bytecode_helper.BytecodeTestCase.assertNotInBytecode" title="Link to this definition">¶</a></dt>

  1499. <dd><p>Throws <a class="reference internal" href="exceptions.html#AssertionError" title="AssertionError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">AssertionError</span></code></a> if <em>opname</em> is found.</p>

  1500. </dd></dl>

  1501. 

  1502. </section>

  1503. <section id="module-test.support.threading_helper">

  1504. <span id="test-support-threading-helper-utilities-for-threading-tests"></span><h1><a class="reference internal" href="#module-test.support.threading_helper" title="test.support.threading_helper: Support for threading tests."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.threading_helper</span></code></a> — Utilities for threading tests<a class="headerlink" href="#module-test.support.threading_helper" title="Link to this heading">¶</a></h1>

  1505. <p>The <a class="reference internal" href="#module-test.support.threading_helper" title="test.support.threading_helper: Support for threading tests."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.threading_helper</span></code></a> module provides support for threading tests.</p>

  1506. <div class="versionadded">

  1507. <p><span class="versionmodified added">New in version 3.10.</span></p>

  1508. </div>

  1509. <dl class="py function">

  1510. <dt class="sig sig-object py" id="test.support.threading_helper.join_thread">

  1511. <span class="sig-prename descclassname"><span class="pre">test.support.threading_helper.</span></span><span class="sig-name descname"><span class="pre">join_thread</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">thread</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">timeout</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.threading_helper.join_thread" title="Link to this definition">¶</a></dt>

  1512. <dd><p>Join a <em>thread</em> within <em>timeout</em>.  Raise an <a class="reference internal" href="exceptions.html#AssertionError" title="AssertionError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">AssertionError</span></code></a> if thread

  1513. is still alive after <em>timeout</em> seconds.</p>

  1514. </dd></dl>

  1515. 

  1516. <dl class="py function">

  1517. <dt class="sig sig-object py" id="test.support.threading_helper.reap_threads">

  1518. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.threading_helper.</span></span><span class="sig-name descname"><span class="pre">reap_threads</span></span><a class="headerlink" href="#test.support.threading_helper.reap_threads" title="Link to this definition">¶</a></dt>

  1519. <dd><p>Decorator to ensure the threads are cleaned up even if the test fails.</p>

  1520. </dd></dl>

  1521. 

  1522. <dl class="py function">

  1523. <dt class="sig sig-object py" id="test.support.threading_helper.start_threads">

  1524. <span class="sig-prename descclassname"><span class="pre">test.support.threading_helper.</span></span><span class="sig-name descname"><span class="pre">start_threads</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">threads</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">unlock</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.threading_helper.start_threads" title="Link to this definition">¶</a></dt>

  1525. <dd><p>Context manager to start <em>threads</em>, which is a sequence of threads.

  1526. <em>unlock</em> is a function called after the threads are started, even if an

  1527. exception was raised; an example would be <a class="reference internal" href="threading.html#threading.Event.set" title="threading.Event.set"><code class="xref py py-meth docutils literal notranslate"><span class="pre">threading.Event.set()</span></code></a>.

  1528. <code class="docutils literal notranslate"><span class="pre">start_threads</span></code> will attempt to join the started threads upon exit.</p>

  1529. </dd></dl>

  1530. 

  1531. <dl class="py function">

  1532. <dt class="sig sig-object py" id="test.support.threading_helper.threading_cleanup">

  1533. <span class="sig-prename descclassname"><span class="pre">test.support.threading_helper.</span></span><span class="sig-name descname"><span class="pre">threading_cleanup</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="o"><span class="pre">*</span></span><span class="n"><span class="pre">original_values</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.threading_helper.threading_cleanup" title="Link to this definition">¶</a></dt>

  1534. <dd><p>Cleanup up threads not specified in <em>original_values</em>.  Designed to emit

  1535. a warning if a test leaves running threads in the background.</p>

  1536. </dd></dl>

  1537. 

  1538. <dl class="py function">

  1539. <dt class="sig sig-object py" id="test.support.threading_helper.threading_setup">

  1540. <span class="sig-prename descclassname"><span class="pre">test.support.threading_helper.</span></span><span class="sig-name descname"><span class="pre">threading_setup</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.threading_helper.threading_setup" title="Link to this definition">¶</a></dt>

  1541. <dd><p>Return current thread count and copy of dangling threads.</p>

  1542. </dd></dl>

  1543. 

  1544. <dl class="py function">

  1545. <dt class="sig sig-object py" id="test.support.threading_helper.wait_threads_exit">

  1546. <span class="sig-prename descclassname"><span class="pre">test.support.threading_helper.</span></span><span class="sig-name descname"><span class="pre">wait_threads_exit</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">timeout</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.threading_helper.wait_threads_exit" title="Link to this definition">¶</a></dt>

  1547. <dd><p>Context manager to wait until all threads created in the <code class="docutils literal notranslate"><span class="pre">with</span></code> statement

  1548. exit.</p>

  1549. </dd></dl>

  1550. 

  1551. <dl class="py function">

  1552. <dt class="sig sig-object py" id="test.support.threading_helper.catch_threading_exception">

  1553. <span class="sig-prename descclassname"><span class="pre">test.support.threading_helper.</span></span><span class="sig-name descname"><span class="pre">catch_threading_exception</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.threading_helper.catch_threading_exception" title="Link to this definition">¶</a></dt>

  1554. <dd><p>Context manager catching <a class="reference internal" href="threading.html#threading.Thread" title="threading.Thread"><code class="xref py py-class docutils literal notranslate"><span class="pre">threading.Thread</span></code></a> exception using

  1555. <a class="reference internal" href="threading.html#threading.excepthook" title="threading.excepthook"><code class="xref py py-func docutils literal notranslate"><span class="pre">threading.excepthook()</span></code></a>.</p>

  1556. <p>Attributes set when an exception is caught:</p>

  1557. <ul class="simple">

  1558. <li><p><code class="docutils literal notranslate"><span class="pre">exc_type</span></code></p></li>

  1559. <li><p><code class="docutils literal notranslate"><span class="pre">exc_value</span></code></p></li>

  1560. <li><p><code class="docutils literal notranslate"><span class="pre">exc_traceback</span></code></p></li>

  1561. <li><p><code class="docutils literal notranslate"><span class="pre">thread</span></code></p></li>

  1562. </ul>

  1563. <p>See <a class="reference internal" href="threading.html#threading.excepthook" title="threading.excepthook"><code class="xref py py-func docutils literal notranslate"><span class="pre">threading.excepthook()</span></code></a> documentation.</p>

  1564. <p>These attributes are deleted at the context manager exit.</p>

  1565. <p>Usage:</p>

  1566. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="k">with</span> <span class="n">threading_helper</span><span class="o">.</span><span class="n">catch_threading_exception</span><span class="p">()</span> <span class="k">as</span> <span class="n">cm</span><span class="p">:</span>

  1567.     <span class="c1"># code spawning a thread which raises an exception</span>

  1568.     <span class="o">...</span>

  1569. 

  1570.     <span class="c1"># check the thread exception, use cm attributes:</span>

  1571.     <span class="c1"># exc_type, exc_value, exc_traceback, thread</span>

  1572.     <span class="o">...</span>

  1573. 

  1574. <span class="c1"># exc_type, exc_value, exc_traceback, thread attributes of cm no longer</span>

  1575. <span class="c1"># exists at this point</span>

  1576. <span class="c1"># (to avoid reference cycles)</span>

  1577. </pre></div>

  1578. </div>

  1579. <div class="versionadded">

  1580. <p><span class="versionmodified added">New in version 3.8.</span></p>

  1581. </div>

  1582. </dd></dl>

  1583. 

  1584. </section>

  1585. <section id="module-test.support.os_helper">

  1586. <span id="test-support-os-helper-utilities-for-os-tests"></span><h1><a class="reference internal" href="#module-test.support.os_helper" title="test.support.os_helper: Support for os tests."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.os_helper</span></code></a> — Utilities for os tests<a class="headerlink" href="#module-test.support.os_helper" title="Link to this heading">¶</a></h1>

  1587. <p>The <a class="reference internal" href="#module-test.support.os_helper" title="test.support.os_helper: Support for os tests."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.os_helper</span></code></a> module provides support for os tests.</p>

  1588. <div class="versionadded">

  1589. <p><span class="versionmodified added">New in version 3.10.</span></p>

  1590. </div>

  1591. <dl class="py data">

  1592. <dt class="sig sig-object py" id="test.support.os_helper.FS_NONASCII">

  1593. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">FS_NONASCII</span></span><a class="headerlink" href="#test.support.os_helper.FS_NONASCII" title="Link to this definition">¶</a></dt>

  1594. <dd><p>A non-ASCII character encodable by <a class="reference internal" href="os.html#os.fsencode" title="os.fsencode"><code class="xref py py-func docutils literal notranslate"><span class="pre">os.fsencode()</span></code></a>.</p>

  1595. </dd></dl>

  1596. 

  1597. <dl class="py data">

  1598. <dt class="sig sig-object py" id="test.support.os_helper.SAVEDCWD">

  1599. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">SAVEDCWD</span></span><a class="headerlink" href="#test.support.os_helper.SAVEDCWD" title="Link to this definition">¶</a></dt>

  1600. <dd><p>Set to <a class="reference internal" href="os.html#os.getcwd" title="os.getcwd"><code class="xref py py-func docutils literal notranslate"><span class="pre">os.getcwd()</span></code></a>.</p>

  1601. </dd></dl>

  1602. 

  1603. <dl class="py data">

  1604. <dt class="sig sig-object py" id="test.support.os_helper.TESTFN">

  1605. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">TESTFN</span></span><a class="headerlink" href="#test.support.os_helper.TESTFN" title="Link to this definition">¶</a></dt>

  1606. <dd><p>Set to a name that is safe to use as the name of a temporary file.  Any

  1607. temporary file that is created should be closed and unlinked (removed).</p>

  1608. </dd></dl>

  1609. 

  1610. <dl class="py data">

  1611. <dt class="sig sig-object py" id="test.support.os_helper.TESTFN_NONASCII">

  1612. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">TESTFN_NONASCII</span></span><a class="headerlink" href="#test.support.os_helper.TESTFN_NONASCII" title="Link to this definition">¶</a></dt>

  1613. <dd><p>Set to a filename containing the <a class="reference internal" href="#test.support.os_helper.FS_NONASCII" title="test.support.os_helper.FS_NONASCII"><code class="xref py py-data docutils literal notranslate"><span class="pre">FS_NONASCII</span></code></a> character, if it exists.

  1614. This guarantees that if the filename exists, it can be encoded and decoded

  1615. with the default filesystem encoding. This allows tests that require a

  1616. non-ASCII filename to be easily skipped on platforms where they can’t work.</p>

  1617. </dd></dl>

  1618. 

  1619. <dl class="py data">

  1620. <dt class="sig sig-object py" id="test.support.os_helper.TESTFN_UNENCODABLE">

  1621. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">TESTFN_UNENCODABLE</span></span><a class="headerlink" href="#test.support.os_helper.TESTFN_UNENCODABLE" title="Link to this definition">¶</a></dt>

  1622. <dd><p>Set to a filename (str type) that should not be able to be encoded by file

  1623. system encoding in strict mode.  It may be <code class="docutils literal notranslate"><span class="pre">None</span></code> if it’s not possible to

  1624. generate such a filename.</p>

  1625. </dd></dl>

  1626. 

  1627. <dl class="py data">

  1628. <dt class="sig sig-object py" id="test.support.os_helper.TESTFN_UNDECODABLE">

  1629. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">TESTFN_UNDECODABLE</span></span><a class="headerlink" href="#test.support.os_helper.TESTFN_UNDECODABLE" title="Link to this definition">¶</a></dt>

  1630. <dd><p>Set to a filename (bytes type) that should not be able to be decoded by

  1631. file system encoding in strict mode.  It may be <code class="docutils literal notranslate"><span class="pre">None</span></code> if it’s not

  1632. possible to generate such a filename.</p>

  1633. </dd></dl>

  1634. 

  1635. <dl class="py data">

  1636. <dt class="sig sig-object py" id="test.support.os_helper.TESTFN_UNICODE">

  1637. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">TESTFN_UNICODE</span></span><a class="headerlink" href="#test.support.os_helper.TESTFN_UNICODE" title="Link to this definition">¶</a></dt>

  1638. <dd><p>Set to a non-ASCII name for a temporary file.</p>

  1639. </dd></dl>

  1640. 

  1641. <dl class="py class">

  1642. <dt class="sig sig-object py" id="test.support.os_helper.EnvironmentVarGuard">

  1643. <em class="property"><span class="pre">class</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">EnvironmentVarGuard</span></span><a class="headerlink" href="#test.support.os_helper.EnvironmentVarGuard" title="Link to this definition">¶</a></dt>

  1644. <dd><p>Class used to temporarily set or unset environment variables.  Instances can

  1645. be used as a context manager and have a complete dictionary interface for

  1646. querying/modifying the underlying <code class="docutils literal notranslate"><span class="pre">os.environ</span></code>. After exit from the

  1647. context manager all changes to environment variables done through this

  1648. instance will be rolled back.</p>

  1649. <div class="versionchanged">

  1650. <p><span class="versionmodified changed">Changed in version 3.1: </span>Added dictionary interface.</p>

  1651. </div>

  1652. </dd></dl>

  1653. 

  1654. <dl class="py class">

  1655. <dt class="sig sig-object py" id="test.support.os_helper.FakePath">

  1656. <em class="property"><span class="pre">class</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">FakePath</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">path</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.os_helper.FakePath" title="Link to this definition">¶</a></dt>

  1657. <dd><p>Simple <a class="reference internal" href="../glossary.html#term-path-like-object"><span class="xref std std-term">path-like object</span></a>.  It implements the

  1658. <a class="reference internal" href="os.html#os.PathLike.__fspath__" title="os.PathLike.__fspath__"><code class="xref py py-meth docutils literal notranslate"><span class="pre">__fspath__()</span></code></a>

  1659. method which just returns the <em>path</em> argument.  If <em>path</em> is an exception,

  1660. it will be raised in <code class="xref py py-meth docutils literal notranslate"><span class="pre">__fspath__()</span></code>.</p>

  1661. </dd></dl>

  1662. 

  1663. <dl class="py method">

  1664. <dt class="sig sig-object py" id="test.support.os_helper.EnvironmentVarGuard.set">

  1665. <span class="sig-prename descclassname"><span class="pre">EnvironmentVarGuard.</span></span><span class="sig-name descname"><span class="pre">set</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">envvar</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">value</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.os_helper.EnvironmentVarGuard.set" title="Link to this definition">¶</a></dt>

  1666. <dd><p>Temporarily set the environment variable <code class="docutils literal notranslate"><span class="pre">envvar</span></code> to the value of

  1667. <code class="docutils literal notranslate"><span class="pre">value</span></code>.</p>

  1668. </dd></dl>

  1669. 

  1670. <dl class="py method">

  1671. <dt class="sig sig-object py" id="test.support.os_helper.EnvironmentVarGuard.unset">

  1672. <span class="sig-prename descclassname"><span class="pre">EnvironmentVarGuard.</span></span><span class="sig-name descname"><span class="pre">unset</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">envvar</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.os_helper.EnvironmentVarGuard.unset" title="Link to this definition">¶</a></dt>

  1673. <dd><p>Temporarily unset the environment variable <code class="docutils literal notranslate"><span class="pre">envvar</span></code>.</p>

  1674. </dd></dl>

  1675. 

  1676. <dl class="py function">

  1677. <dt class="sig sig-object py" id="test.support.os_helper.can_symlink">

  1678. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">can_symlink</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.os_helper.can_symlink" title="Link to this definition">¶</a></dt>

  1679. <dd><p>Return <code class="docutils literal notranslate"><span class="pre">True</span></code> if the OS supports symbolic links, <code class="docutils literal notranslate"><span class="pre">False</span></code>

  1680. otherwise.</p>

  1681. </dd></dl>

  1682. 

  1683. <dl class="py function">

  1684. <dt class="sig sig-object py" id="test.support.os_helper.can_xattr">

  1685. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">can_xattr</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.os_helper.can_xattr" title="Link to this definition">¶</a></dt>

  1686. <dd><p>Return <code class="docutils literal notranslate"><span class="pre">True</span></code> if the OS supports xattr, <code class="docutils literal notranslate"><span class="pre">False</span></code>

  1687. otherwise.</p>

  1688. </dd></dl>

  1689. 

  1690. <dl class="py function">

  1691. <dt class="sig sig-object py" id="test.support.os_helper.change_cwd">

  1692. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">change_cwd</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">path</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">quiet</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">False</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.os_helper.change_cwd" title="Link to this definition">¶</a></dt>

  1693. <dd><p>A context manager that temporarily changes the current working

  1694. directory to <em>path</em> and yields the directory.</p>

  1695. <p>If <em>quiet</em> is <code class="docutils literal notranslate"><span class="pre">False</span></code>, the context manager raises an exception

  1696. on error.  Otherwise, it issues only a warning and keeps the current

  1697. working directory the same.</p>

  1698. </dd></dl>

  1699. 

  1700. <dl class="py function">

  1701. <dt class="sig sig-object py" id="test.support.os_helper.create_empty_file">

  1702. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">create_empty_file</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">filename</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.os_helper.create_empty_file" title="Link to this definition">¶</a></dt>

  1703. <dd><p>Create an empty file with <em>filename</em>.  If it already exists, truncate it.</p>

  1704. </dd></dl>

  1705. 

  1706. <dl class="py function">

  1707. <dt class="sig sig-object py" id="test.support.os_helper.fd_count">

  1708. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">fd_count</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.os_helper.fd_count" title="Link to this definition">¶</a></dt>

  1709. <dd><p>Count the number of open file descriptors.</p>

  1710. </dd></dl>

  1711. 

  1712. <dl class="py function">

  1713. <dt class="sig sig-object py" id="test.support.os_helper.fs_is_case_insensitive">

  1714. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">fs_is_case_insensitive</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">directory</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.os_helper.fs_is_case_insensitive" title="Link to this definition">¶</a></dt>

  1715. <dd><p>Return <code class="docutils literal notranslate"><span class="pre">True</span></code> if the file system for <em>directory</em> is case-insensitive.</p>

  1716. </dd></dl>

  1717. 

  1718. <dl class="py function">

  1719. <dt class="sig sig-object py" id="test.support.os_helper.make_bad_fd">

  1720. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">make_bad_fd</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.os_helper.make_bad_fd" title="Link to this definition">¶</a></dt>

  1721. <dd><p>Create an invalid file descriptor by opening and closing a temporary file,

  1722. and returning its descriptor.</p>

  1723. </dd></dl>

  1724. 

  1725. <dl class="py function">

  1726. <dt class="sig sig-object py" id="test.support.os_helper.rmdir">

  1727. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">rmdir</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">filename</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.os_helper.rmdir" title="Link to this definition">¶</a></dt>

  1728. <dd><p>Call <a class="reference internal" href="os.html#os.rmdir" title="os.rmdir"><code class="xref py py-func docutils literal notranslate"><span class="pre">os.rmdir()</span></code></a> on <em>filename</em>.  On Windows platforms, this is

  1729. wrapped with a wait loop that checks for the existence of the file,

  1730. which is needed due to antivirus programs that can hold files open and prevent

  1731. deletion.</p>

  1732. </dd></dl>

  1733. 

  1734. <dl class="py function">

  1735. <dt class="sig sig-object py" id="test.support.os_helper.rmtree">

  1736. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">rmtree</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">path</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.os_helper.rmtree" title="Link to this definition">¶</a></dt>

  1737. <dd><p>Call <a class="reference internal" href="shutil.html#shutil.rmtree" title="shutil.rmtree"><code class="xref py py-func docutils literal notranslate"><span class="pre">shutil.rmtree()</span></code></a> on <em>path</em> or call <a class="reference internal" href="os.html#os.lstat" title="os.lstat"><code class="xref py py-func docutils literal notranslate"><span class="pre">os.lstat()</span></code></a> and

  1738. <a class="reference internal" href="os.html#os.rmdir" title="os.rmdir"><code class="xref py py-func docutils literal notranslate"><span class="pre">os.rmdir()</span></code></a> to remove a path and its contents.  As with <a class="reference internal" href="#test.support.os_helper.rmdir" title="test.support.os_helper.rmdir"><code class="xref py py-func docutils literal notranslate"><span class="pre">rmdir()</span></code></a>,

  1739. on Windows platforms

  1740. this is wrapped with a wait loop that checks for the existence of the files.</p>

  1741. </dd></dl>

  1742. 

  1743. <dl class="py function">

  1744. <dt class="sig sig-object py" id="test.support.os_helper.skip_unless_symlink">

  1745. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">skip_unless_symlink</span></span><a class="headerlink" href="#test.support.os_helper.skip_unless_symlink" title="Link to this definition">¶</a></dt>

  1746. <dd><p>A decorator for running tests that require support for symbolic links.</p>

  1747. </dd></dl>

  1748. 

  1749. <dl class="py function">

  1750. <dt class="sig sig-object py" id="test.support.os_helper.skip_unless_xattr">

  1751. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">skip_unless_xattr</span></span><a class="headerlink" href="#test.support.os_helper.skip_unless_xattr" title="Link to this definition">¶</a></dt>

  1752. <dd><p>A decorator for running tests that require support for xattr.</p>

  1753. </dd></dl>

  1754. 

  1755. <dl class="py function">

  1756. <dt class="sig sig-object py" id="test.support.os_helper.temp_cwd">

  1757. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">temp_cwd</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">name</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">'tempcwd'</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">quiet</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">False</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.os_helper.temp_cwd" title="Link to this definition">¶</a></dt>

  1758. <dd><p>A context manager that temporarily creates a new directory and

  1759. changes the current working directory (CWD).</p>

  1760. <p>The context manager creates a temporary directory in the current

  1761. directory with name <em>name</em> before temporarily changing the current

  1762. working directory.  If <em>name</em> is <code class="docutils literal notranslate"><span class="pre">None</span></code>, the temporary directory is

  1763. created using <a class="reference internal" href="tempfile.html#tempfile.mkdtemp" title="tempfile.mkdtemp"><code class="xref py py-func docutils literal notranslate"><span class="pre">tempfile.mkdtemp()</span></code></a>.</p>

  1764. <p>If <em>quiet</em> is <code class="docutils literal notranslate"><span class="pre">False</span></code> and it is not possible to create or change

  1765. the CWD, an error is raised.  Otherwise, only a warning is raised

  1766. and the original CWD is used.</p>

  1767. </dd></dl>

  1768. 

  1769. <dl class="py function">

  1770. <dt class="sig sig-object py" id="test.support.os_helper.temp_dir">

  1771. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">temp_dir</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">path</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">quiet</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">False</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.os_helper.temp_dir" title="Link to this definition">¶</a></dt>

  1772. <dd><p>A context manager that creates a temporary directory at <em>path</em> and

  1773. yields the directory.</p>

  1774. <p>If <em>path</em> is <code class="docutils literal notranslate"><span class="pre">None</span></code>, the temporary directory is created using

  1775. <a class="reference internal" href="tempfile.html#tempfile.mkdtemp" title="tempfile.mkdtemp"><code class="xref py py-func docutils literal notranslate"><span class="pre">tempfile.mkdtemp()</span></code></a>.  If <em>quiet</em> is <code class="docutils literal notranslate"><span class="pre">False</span></code>, the context manager

  1776. raises an exception on error.  Otherwise, if <em>path</em> is specified and

  1777. cannot be created, only a warning is issued.</p>

  1778. </dd></dl>

  1779. 

  1780. <dl class="py function">

  1781. <dt class="sig sig-object py" id="test.support.os_helper.temp_umask">

  1782. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">temp_umask</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">umask</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.os_helper.temp_umask" title="Link to this definition">¶</a></dt>

  1783. <dd><p>A context manager that temporarily sets the process umask.</p>

  1784. </dd></dl>

  1785. 

  1786. <dl class="py function">

  1787. <dt class="sig sig-object py" id="test.support.os_helper.unlink">

  1788. <span class="sig-prename descclassname"><span class="pre">test.support.os_helper.</span></span><span class="sig-name descname"><span class="pre">unlink</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">filename</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.os_helper.unlink" title="Link to this definition">¶</a></dt>

  1789. <dd><p>Call <a class="reference internal" href="os.html#os.unlink" title="os.unlink"><code class="xref py py-func docutils literal notranslate"><span class="pre">os.unlink()</span></code></a> on <em>filename</em>.  As with <a class="reference internal" href="#test.support.os_helper.rmdir" title="test.support.os_helper.rmdir"><code class="xref py py-func docutils literal notranslate"><span class="pre">rmdir()</span></code></a>,

  1790. on Windows platforms, this is

  1791. wrapped with a wait loop that checks for the existence of the file.</p>

  1792. </dd></dl>

  1793. 

  1794. </section>

  1795. <section id="module-test.support.import_helper">

  1796. <span id="test-support-import-helper-utilities-for-import-tests"></span><h1><a class="reference internal" href="#module-test.support.import_helper" title="test.support.import_helper: Support for import tests."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.import_helper</span></code></a> — Utilities for import tests<a class="headerlink" href="#module-test.support.import_helper" title="Link to this heading">¶</a></h1>

  1797. <p>The <a class="reference internal" href="#module-test.support.import_helper" title="test.support.import_helper: Support for import tests."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.import_helper</span></code></a> module provides support for import tests.</p>

  1798. <div class="versionadded">

  1799. <p><span class="versionmodified added">New in version 3.10.</span></p>

  1800. </div>

  1801. <dl class="py function">

  1802. <dt class="sig sig-object py" id="test.support.import_helper.forget">

  1803. <span class="sig-prename descclassname"><span class="pre">test.support.import_helper.</span></span><span class="sig-name descname"><span class="pre">forget</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">module_name</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.import_helper.forget" title="Link to this definition">¶</a></dt>

  1804. <dd><p>Remove the module named <em>module_name</em> from <code class="docutils literal notranslate"><span class="pre">sys.modules</span></code> and delete any

  1805. byte-compiled files of the module.</p>

  1806. </dd></dl>

  1807. 

  1808. <dl class="py function">

  1809. <dt class="sig sig-object py" id="test.support.import_helper.import_fresh_module">

  1810. <span class="sig-prename descclassname"><span class="pre">test.support.import_helper.</span></span><span class="sig-name descname"><span class="pre">import_fresh_module</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">name</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">fresh</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">()</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">blocked</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">()</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">deprecated</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">False</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.import_helper.import_fresh_module" title="Link to this definition">¶</a></dt>

  1811. <dd><p>This function imports and returns a fresh copy of the named Python module

  1812. by removing the named module from <code class="docutils literal notranslate"><span class="pre">sys.modules</span></code> before doing the import.

  1813. Note that unlike <code class="xref py py-func docutils literal notranslate"><span class="pre">reload()</span></code>, the original module is not affected by

  1814. this operation.</p>

  1815. <p><em>fresh</em> is an iterable of additional module names that are also removed

  1816. from the <code class="docutils literal notranslate"><span class="pre">sys.modules</span></code> cache before doing the import.</p>

  1817. <p><em>blocked</em> is an iterable of module names that are replaced with <code class="docutils literal notranslate"><span class="pre">None</span></code>

  1818. in the module cache during the import to ensure that attempts to import

  1819. them raise <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ImportError</span></code></a>.</p>

  1820. <p>The named module and any modules named in the <em>fresh</em> and <em>blocked</em>

  1821. parameters are saved before starting the import and then reinserted into

  1822. <code class="docutils literal notranslate"><span class="pre">sys.modules</span></code> when the fresh import is complete.</p>

  1823. <p>Module and package deprecation messages are suppressed during this import

  1824. if <em>deprecated</em> is <code class="docutils literal notranslate"><span class="pre">True</span></code>.</p>

  1825. <p>This function will raise <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ImportError</span></code></a> if the named module cannot be

  1826. imported.</p>

  1827. <p>Example use:</p>

  1828. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="c1"># Get copies of the warnings module for testing without affecting the</span>

  1829. <span class="c1"># version being used by the rest of the test suite. One copy uses the</span>

  1830. <span class="c1"># C implementation, the other is forced to use the pure Python fallback</span>

  1831. <span class="c1"># implementation</span>

  1832. <span class="n">py_warnings</span> <span class="o">=</span> <span class="n">import_fresh_module</span><span class="p">(</span><span class="s1">&#39;warnings&#39;</span><span class="p">,</span> <span class="n">blocked</span><span class="o">=</span><span class="p">[</span><span class="s1">&#39;_warnings&#39;</span><span class="p">])</span>

  1833. <span class="n">c_warnings</span> <span class="o">=</span> <span class="n">import_fresh_module</span><span class="p">(</span><span class="s1">&#39;warnings&#39;</span><span class="p">,</span> <span class="n">fresh</span><span class="o">=</span><span class="p">[</span><span class="s1">&#39;_warnings&#39;</span><span class="p">])</span>

  1834. </pre></div>

  1835. </div>

  1836. <div class="versionadded">

  1837. <p><span class="versionmodified added">New in version 3.1.</span></p>

  1838. </div>

  1839. </dd></dl>

  1840. 

  1841. <dl class="py function">

  1842. <dt class="sig sig-object py" id="test.support.import_helper.import_module">

  1843. <span class="sig-prename descclassname"><span class="pre">test.support.import_helper.</span></span><span class="sig-name descname"><span class="pre">import_module</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">name</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">deprecated</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">False</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">*</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">required_on</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">()</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.import_helper.import_module" title="Link to this definition">¶</a></dt>

  1844. <dd><p>This function imports and returns the named module. Unlike a normal

  1845. import, this function raises <a class="reference internal" href="unittest.html#unittest.SkipTest" title="unittest.SkipTest"><code class="xref py py-exc docutils literal notranslate"><span class="pre">unittest.SkipTest</span></code></a> if the module

  1846. cannot be imported.</p>

  1847. <p>Module and package deprecation messages are suppressed during this import

  1848. if <em>deprecated</em> is <code class="docutils literal notranslate"><span class="pre">True</span></code>.  If a module is required on a platform but

  1849. optional for others, set <em>required_on</em> to an iterable of platform prefixes

  1850. which will be compared against <a class="reference internal" href="sys.html#sys.platform" title="sys.platform"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.platform</span></code></a>.</p>

  1851. <div class="versionadded">

  1852. <p><span class="versionmodified added">New in version 3.1.</span></p>

  1853. </div>

  1854. </dd></dl>

  1855. 

  1856. <dl class="py function">

  1857. <dt class="sig sig-object py" id="test.support.import_helper.modules_setup">

  1858. <span class="sig-prename descclassname"><span class="pre">test.support.import_helper.</span></span><span class="sig-name descname"><span class="pre">modules_setup</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#test.support.import_helper.modules_setup" title="Link to this definition">¶</a></dt>

  1859. <dd><p>Return a copy of <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.modules</span></code></a>.</p>

  1860. </dd></dl>

  1861. 

  1862. <dl class="py function">

  1863. <dt class="sig sig-object py" id="test.support.import_helper.modules_cleanup">

  1864. <span class="sig-prename descclassname"><span class="pre">test.support.import_helper.</span></span><span class="sig-name descname"><span class="pre">modules_cleanup</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">oldmodules</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.import_helper.modules_cleanup" title="Link to this definition">¶</a></dt>

  1865. <dd><p>Remove modules except for <em>oldmodules</em> and <code class="docutils literal notranslate"><span class="pre">encodings</span></code> in order to

  1866. preserve internal cache.</p>

  1867. </dd></dl>

  1868. 

  1869. <dl class="py function">

  1870. <dt class="sig sig-object py" id="test.support.import_helper.unload">

  1871. <span class="sig-prename descclassname"><span class="pre">test.support.import_helper.</span></span><span class="sig-name descname"><span class="pre">unload</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">name</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.import_helper.unload" title="Link to this definition">¶</a></dt>

  1872. <dd><p>Delete <em>name</em> from <code class="docutils literal notranslate"><span class="pre">sys.modules</span></code>.</p>

  1873. </dd></dl>

  1874. 

  1875. <dl class="py function">

  1876. <dt class="sig sig-object py" id="test.support.import_helper.make_legacy_pyc">

  1877. <span class="sig-prename descclassname"><span class="pre">test.support.import_helper.</span></span><span class="sig-name descname"><span class="pre">make_legacy_pyc</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">source</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.import_helper.make_legacy_pyc" title="Link to this definition">¶</a></dt>

  1878. <dd><p>Move a <span class="target" id="index-3"></span><a class="pep reference external" href="https://peps.python.org/pep-3147/"><strong>PEP 3147</strong></a>/<span class="target" id="index-4"></span><a class="pep reference external" href="https://peps.python.org/pep-0488/"><strong>PEP 488</strong></a> pyc file to its legacy pyc location and return the file

  1879. system path to the legacy pyc file.  The <em>source</em> value is the file system

  1880. path to the source file.  It does not need to exist, however the PEP

  1881. 3147/488 pyc file must exist.</p>

  1882. </dd></dl>

  1883. 

  1884. <dl class="py class">

  1885. <dt class="sig sig-object py" id="test.support.import_helper.CleanImport">

  1886. <em class="property"><span class="pre">class</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">test.support.import_helper.</span></span><span class="sig-name descname"><span class="pre">CleanImport</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="o"><span class="pre">*</span></span><span class="n"><span class="pre">module_names</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.import_helper.CleanImport" title="Link to this definition">¶</a></dt>

  1887. <dd><p>A context manager to force import to return a new module reference.  This

  1888. is useful for testing module-level behaviors, such as the emission of a

  1889. <a class="reference internal" href="exceptions.html#DeprecationWarning" title="DeprecationWarning"><code class="xref py py-exc docutils literal notranslate"><span class="pre">DeprecationWarning</span></code></a> on import.  Example usage:</p>

  1890. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="k">with</span> <span class="n">CleanImport</span><span class="p">(</span><span class="s1">&#39;foo&#39;</span><span class="p">):</span>

  1891.     <span class="n">importlib</span><span class="o">.</span><span class="n">import_module</span><span class="p">(</span><span class="s1">&#39;foo&#39;</span><span class="p">)</span>  <span class="c1"># New reference.</span>

  1892. </pre></div>

  1893. </div>

  1894. </dd></dl>

  1895. 

  1896. <dl class="py class">

  1897. <dt class="sig sig-object py" id="test.support.import_helper.DirsOnSysPath">

  1898. <em class="property"><span class="pre">class</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">test.support.import_helper.</span></span><span class="sig-name descname"><span class="pre">DirsOnSysPath</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="o"><span class="pre">*</span></span><span class="n"><span class="pre">paths</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.import_helper.DirsOnSysPath" title="Link to this definition">¶</a></dt>

  1899. <dd><p>A context manager to temporarily add directories to <a class="reference internal" href="sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.path</span></code></a>.</p>

  1900. <p>This makes a copy of <a class="reference internal" href="sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.path</span></code></a>, appends any directories given

  1901. as positional arguments, then reverts <a class="reference internal" href="sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.path</span></code></a> to the copied

  1902. settings when the context ends.</p>

  1903. <p>Note that <em>all</em> <a class="reference internal" href="sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.path</span></code></a> modifications in the body of the

  1904. context manager, including replacement of the object,

  1905. will be reverted at the end of the block.</p>

  1906. </dd></dl>

  1907. 

  1908. </section>

  1909. <section id="module-test.support.warnings_helper">

  1910. <span id="test-support-warnings-helper-utilities-for-warnings-tests"></span><h1><a class="reference internal" href="#module-test.support.warnings_helper" title="test.support.warnings_helper: Support for warnings tests."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.warnings_helper</span></code></a> — Utilities for warnings tests<a class="headerlink" href="#module-test.support.warnings_helper" title="Link to this heading">¶</a></h1>

  1911. <p>The <a class="reference internal" href="#module-test.support.warnings_helper" title="test.support.warnings_helper: Support for warnings tests."><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.warnings_helper</span></code></a> module provides support for warnings tests.</p>

  1912. <div class="versionadded">

  1913. <p><span class="versionmodified added">New in version 3.10.</span></p>

  1914. </div>

  1915. <dl class="py function">

  1916. <dt class="sig sig-object py" id="test.support.warnings_helper.ignore_warnings">

  1917. <span class="sig-prename descclassname"><span class="pre">test.support.warnings_helper.</span></span><span class="sig-name descname"><span class="pre">ignore_warnings</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="o"><span class="pre">*</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">category</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.warnings_helper.ignore_warnings" title="Link to this definition">¶</a></dt>

  1918. <dd><p>Suppress warnings that are instances of <em>category</em>,

  1919. which must be <a class="reference internal" href="exceptions.html#Warning" title="Warning"><code class="xref py py-exc docutils literal notranslate"><span class="pre">Warning</span></code></a> or a subclass.

  1920. Roughly equivalent to <a class="reference internal" href="warnings.html#warnings.catch_warnings" title="warnings.catch_warnings"><code class="xref py py-func docutils literal notranslate"><span class="pre">warnings.catch_warnings()</span></code></a>

  1921. with <a class="reference internal" href="warnings.html#warnings.simplefilter" title="warnings.simplefilter"><code class="xref py py-meth docutils literal notranslate"><span class="pre">warnings.simplefilter('ignore',</span> <span class="pre">category=category)</span></code></a>.

  1922. For example:</p>

  1923. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="nd">@warning_helper</span><span class="o">.</span><span class="n">ignore_warnings</span><span class="p">(</span><span class="n">category</span><span class="o">=</span><span class="ne">DeprecationWarning</span><span class="p">)</span>

  1924. <span class="k">def</span> <span class="nf">test_suppress_warning</span><span class="p">():</span>

  1925.     <span class="c1"># do something</span>

  1926. </pre></div>

  1927. </div>

  1928. <div class="versionadded">

  1929. <p><span class="versionmodified added">New in version 3.8.</span></p>

  1930. </div>

  1931. </dd></dl>

  1932. 

  1933. <dl class="py function">

  1934. <dt class="sig sig-object py" id="test.support.warnings_helper.check_no_resource_warning">

  1935. <span class="sig-prename descclassname"><span class="pre">test.support.warnings_helper.</span></span><span class="sig-name descname"><span class="pre">check_no_resource_warning</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">testcase</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.warnings_helper.check_no_resource_warning" title="Link to this definition">¶</a></dt>

  1936. <dd><p>Context manager to check that no <a class="reference internal" href="exceptions.html#ResourceWarning" title="ResourceWarning"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ResourceWarning</span></code></a> was raised.  You

  1937. must remove the object which may emit <a class="reference internal" href="exceptions.html#ResourceWarning" title="ResourceWarning"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ResourceWarning</span></code></a> before the

  1938. end of the context manager.</p>

  1939. </dd></dl>

  1940. 

  1941. <dl class="py function">

  1942. <dt class="sig sig-object py" id="test.support.warnings_helper.check_syntax_warning">

  1943. <span class="sig-prename descclassname"><span class="pre">test.support.warnings_helper.</span></span><span class="sig-name descname"><span class="pre">check_syntax_warning</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">testcase</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">statement</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">errtext</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">''</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">*</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">lineno</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">1</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">offset</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.warnings_helper.check_syntax_warning" title="Link to this definition">¶</a></dt>

  1944. <dd><p>Test for syntax warning in <em>statement</em> by attempting to compile <em>statement</em>.

  1945. Test also that the <a class="reference internal" href="exceptions.html#SyntaxWarning" title="SyntaxWarning"><code class="xref py py-exc docutils literal notranslate"><span class="pre">SyntaxWarning</span></code></a> is emitted only once, and that it

  1946. will be converted to a <a class="reference internal" href="exceptions.html#SyntaxError" title="SyntaxError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">SyntaxError</span></code></a> when turned into error.

  1947. <em>testcase</em> is the <a class="reference internal" href="unittest.html#module-unittest" title="unittest: Unit testing framework for Python."><code class="xref py py-mod docutils literal notranslate"><span class="pre">unittest</span></code></a> instance for the test.  <em>errtext</em> is the

  1948. regular expression which should match the string representation of the

  1949. emitted <a class="reference internal" href="exceptions.html#SyntaxWarning" title="SyntaxWarning"><code class="xref py py-exc docutils literal notranslate"><span class="pre">SyntaxWarning</span></code></a> and raised <a class="reference internal" href="exceptions.html#SyntaxError" title="SyntaxError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">SyntaxError</span></code></a>.  If <em>lineno</em>

  1950. is not <code class="docutils literal notranslate"><span class="pre">None</span></code>, compares to the line of the warning and exception.

  1951. If <em>offset</em> is not <code class="docutils literal notranslate"><span class="pre">None</span></code>, compares to the offset of the exception.</p>

  1952. <div class="versionadded">

  1953. <p><span class="versionmodified added">New in version 3.8.</span></p>

  1954. </div>

  1955. </dd></dl>

  1956. 

  1957. <dl class="py function">

  1958. <dt class="sig sig-object py" id="test.support.warnings_helper.check_warnings">

  1959. <span class="sig-prename descclassname"><span class="pre">test.support.warnings_helper.</span></span><span class="sig-name descname"><span class="pre">check_warnings</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="o"><span class="pre">*</span></span><span class="n"><span class="pre">filters</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">quiet</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">True</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#test.support.warnings_helper.check_warnings" title="Link to this definition">¶</a></dt>

  1960. <dd><p>A convenience wrapper for <a class="reference internal" href="warnings.html#warnings.catch_warnings" title="warnings.catch_warnings"><code class="xref py py-func docutils literal notranslate"><span class="pre">warnings.catch_warnings()</span></code></a> that makes it

  1961. easier to test that a warning was correctly raised.  It is approximately

  1962. equivalent to calling <code class="docutils literal notranslate"><span class="pre">warnings.catch_warnings(record=True)</span></code> with

  1963. <a class="reference internal" href="warnings.html#warnings.simplefilter" title="warnings.simplefilter"><code class="xref py py-meth docutils literal notranslate"><span class="pre">warnings.simplefilter()</span></code></a> set to <code class="docutils literal notranslate"><span class="pre">always</span></code> and with the option to

  1964. automatically validate the results that are recorded.</p>

  1965. <p><code class="docutils literal notranslate"><span class="pre">check_warnings</span></code> accepts 2-tuples of the form <code class="docutils literal notranslate"><span class="pre">(&quot;message</span> <span class="pre">regexp&quot;,</span>

  1966. <span class="pre">WarningCategory)</span></code> as positional arguments. If one or more <em>filters</em> are

  1967. provided, or if the optional keyword argument <em>quiet</em> is <code class="docutils literal notranslate"><span class="pre">False</span></code>,

  1968. it checks to make sure the warnings are as expected:  each specified filter

  1969. must match at least one of the warnings raised by the enclosed code or the

  1970. test fails, and if any warnings are raised that do not match any of the

  1971. specified filters the test fails.  To disable the first of these checks,

  1972. set <em>quiet</em> to <code class="docutils literal notranslate"><span class="pre">True</span></code>.</p>

  1973. <p>If no arguments are specified, it defaults to:</p>

  1974. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="n">check_warnings</span><span class="p">((</span><span class="s2">&quot;&quot;</span><span class="p">,</span> <span class="ne">Warning</span><span class="p">),</span> <span class="n">quiet</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>

  1975. </pre></div>

  1976. </div>

  1977. <p>In this case all warnings are caught and no errors are raised.</p>

  1978. <p>On entry to the context manager, a <code class="xref py py-class docutils literal notranslate"><span class="pre">WarningRecorder</span></code> instance is

  1979. returned. The underlying warnings list from

  1980. <a class="reference internal" href="warnings.html#warnings.catch_warnings" title="warnings.catch_warnings"><code class="xref py py-func docutils literal notranslate"><span class="pre">catch_warnings()</span></code></a> is available via the recorder object’s

  1981. <a class="reference internal" href="warnings.html#module-warnings" title="warnings: Issue warning messages and control their disposition."><code class="xref py py-attr docutils literal notranslate"><span class="pre">warnings</span></code></a> attribute.  As a convenience, the attributes of the object

  1982. representing the most recent warning can also be accessed directly through

  1983. the recorder object (see example below).  If no warning has been raised,

  1984. then any of the attributes that would otherwise be expected on an object

  1985. representing a warning will return <code class="docutils literal notranslate"><span class="pre">None</span></code>.</p>

  1986. <p>The recorder object also has a <code class="xref py py-meth docutils literal notranslate"><span class="pre">reset()</span></code> method, which clears the

  1987. warnings list.</p>

  1988. <p>The context manager is designed to be used like this:</p>

  1989. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="k">with</span> <span class="n">check_warnings</span><span class="p">((</span><span class="s2">&quot;assertion is always true&quot;</span><span class="p">,</span> <span class="ne">SyntaxWarning</span><span class="p">),</span>

  1990.                     <span class="p">(</span><span class="s2">&quot;&quot;</span><span class="p">,</span> <span class="ne">UserWarning</span><span class="p">)):</span>

  1991.     <span class="n">exec</span><span class="p">(</span><span class="s1">&#39;assert(False, &quot;Hey!&quot;)&#39;</span><span class="p">)</span>

  1992.     <span class="n">warnings</span><span class="o">.</span><span class="n">warn</span><span class="p">(</span><span class="ne">UserWarning</span><span class="p">(</span><span class="s2">&quot;Hide me!&quot;</span><span class="p">))</span>

  1993. </pre></div>

  1994. </div>

  1995. <p>In this case if either warning was not raised, or some other warning was

  1996. raised, <a class="reference internal" href="#test.support.warnings_helper.check_warnings" title="test.support.warnings_helper.check_warnings"><code class="xref py py-func docutils literal notranslate"><span class="pre">check_warnings()</span></code></a> would raise an error.</p>

  1997. <p>When a test needs to look more deeply into the warnings, rather than

  1998. just checking whether or not they occurred, code like this can be used:</p>

  1999. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="k">with</span> <span class="n">check_warnings</span><span class="p">(</span><span class="n">quiet</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span> <span class="k">as</span> <span class="n">w</span><span class="p">:</span>

  2000.     <span class="n">warnings</span><span class="o">.</span><span class="n">warn</span><span class="p">(</span><span class="s2">&quot;foo&quot;</span><span class="p">)</span>

  2001.     <span class="k">assert</span> <span class="nb">str</span><span class="p">(</span><span class="n">w</span><span class="o">.</span><span class="n">args</span><span class="p">[</span><span class="mi">0</span><span class="p">])</span> <span class="o">==</span> <span class="s2">&quot;foo&quot;</span>

  2002.     <span class="n">warnings</span><span class="o">.</span><span class="n">warn</span><span class="p">(</span><span class="s2">&quot;bar&quot;</span><span class="p">)</span>

  2003.     <span class="k">assert</span> <span class="nb">str</span><span class="p">(</span><span class="n">w</span><span class="o">.</span><span class="n">args</span><span class="p">[</span><span class="mi">0</span><span class="p">])</span> <span class="o">==</span> <span class="s2">&quot;bar&quot;</span>

  2004.     <span class="k">assert</span> <span class="nb">str</span><span class="p">(</span><span class="n">w</span><span class="o">.</span><span class="n">warnings</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">args</span><span class="p">[</span><span class="mi">0</span><span class="p">])</span> <span class="o">==</span> <span class="s2">&quot;foo&quot;</span>

  2005.     <span class="k">assert</span> <span class="nb">str</span><span class="p">(</span><span class="n">w</span><span class="o">.</span><span class="n">warnings</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span><span class="o">.</span><span class="n">args</span><span class="p">[</span><span class="mi">0</span><span class="p">])</span> <span class="o">==</span> <span class="s2">&quot;bar&quot;</span>

  2006.     <span class="n">w</span><span class="o">.</span><span class="n">reset</span><span class="p">()</span>

  2007.     <span class="k">assert</span> <span class="nb">len</span><span class="p">(</span><span class="n">w</span><span class="o">.</span><span class="n">warnings</span><span class="p">)</span> <span class="o">==</span> <span class="mi">0</span>

  2008. </pre></div>

  2009. </div>

  2010. <p>Here all warnings will be caught, and the test code tests the captured

  2011. warnings directly.</p>

  2012. <div class="versionchanged">

  2013. <p><span class="versionmodified changed">Changed in version 3.2: </span>New optional arguments <em>filters</em> and <em>quiet</em>.</p>

  2014. </div>

  2015. </dd></dl>

  2016. 

  2017. <dl class="py class">

  2018. <dt class="sig sig-object py" id="test.support.warnings_helper.WarningsRecorder">

  2019. <em class="property"><span class="pre">class</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">test.support.warnings_helper.</span></span><span class="sig-name descname"><span class="pre">WarningsRecorder</span></span><a class="headerlink" href="#test.support.warnings_helper.WarningsRecorder" title="Link to this definition">¶</a></dt>

  2020. <dd><p>Class used to record warnings for unit tests. See documentation of

  2021. <a class="reference internal" href="#test.support.warnings_helper.check_warnings" title="test.support.warnings_helper.check_warnings"><code class="xref py py-func docutils literal notranslate"><span class="pre">check_warnings()</span></code></a> above for more details.</p>

  2022. </dd></dl>

  2023. 

  2024. </section>

  2025. 

  2026. 

  2027.             <div class="clearer"></div>

  2028.           </div>

  2029.         </div>

  2030.       </div>

  2031.       <div class="sphinxsidebar" role="navigation" aria-label="main navigation">

  2032.         <div class="sphinxsidebarwrapper">

  2033.   <div>

  2034.     <h3><a href="../contents.html">Table of Contents</a></h3>

  2035.     <ul>

  2036. <li><a class="reference internal" href="#"><code class="xref py py-mod docutils literal notranslate"><span class="pre">test</span></code> — Regression tests package for Python</a><ul>

  2037. <li><a class="reference internal" href="#writing-unit-tests-for-the-test-package">Writing Unit Tests for the <code class="xref py py-mod docutils literal notranslate"><span class="pre">test</span></code> package</a></li>

  2038. <li><a class="reference internal" href="#module-test.regrtest">Running tests using the command-line interface</a></li>

  2039. </ul>

  2040. </li>

  2041. <li><a class="reference internal" href="#module-test.support"><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support</span></code> — Utilities for the Python test suite</a></li>

  2042. <li><a class="reference internal" href="#module-test.support.socket_helper"><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.socket_helper</span></code> — Utilities for socket tests</a></li>

  2043. <li><a class="reference internal" href="#module-test.support.script_helper"><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.script_helper</span></code> — Utilities for the Python execution tests</a></li>

  2044. <li><a class="reference internal" href="#module-test.support.bytecode_helper"><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.bytecode_helper</span></code> — Support tools for testing correct bytecode generation</a></li>

  2045. <li><a class="reference internal" href="#module-test.support.threading_helper"><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.threading_helper</span></code> — Utilities for threading tests</a></li>

  2046. <li><a class="reference internal" href="#module-test.support.os_helper"><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.os_helper</span></code> — Utilities for os tests</a></li>

  2047. <li><a class="reference internal" href="#module-test.support.import_helper"><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.import_helper</span></code> — Utilities for import tests</a></li>

  2048. <li><a class="reference internal" href="#module-test.support.warnings_helper"><code class="xref py py-mod docutils literal notranslate"><span class="pre">test.support.warnings_helper</span></code> — Utilities for warnings tests</a></li>

  2049. </ul>

  2050. 

  2051.   </div>

  2052.   <div>

  2053.     <h4>Previous topic</h4>

  2054.     <p class="topless"><a href="2to3.html"

  2055.                           title="previous chapter">2to3 — Automated Python 2 to 3 code translation</a></p>

  2056.   </div>

  2057.   <div>

  2058.     <h4>Next topic</h4>

  2059.     <p class="topless"><a href="debug.html"

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