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  98. <li><a class="reference internal" href="#"><code class="xref py py-mod docutils literal notranslate"><span class="pre">venv</span></code> — Creation of virtual environments</a><ul>

  99. <li><a class="reference internal" href="#creating-virtual-environments">Creating virtual environments</a></li>

  100. <li><a class="reference internal" href="#how-venvs-work">How venvs work</a></li>

  101. <li><a class="reference internal" href="#api">API</a></li>

  102. <li><a class="reference internal" href="#an-example-of-extending-envbuilder">An example of extending <code class="docutils literal notranslate"><span class="pre">EnvBuilder</span></code></a></li>

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  195.   <section id="module-venv">

  196. <span id="venv-creation-of-virtual-environments"></span><h1><a class="reference internal" href="#module-venv" title="venv: Creation of virtual environments."><code class="xref py py-mod docutils literal notranslate"><span class="pre">venv</span></code></a> — Creation of virtual environments<a class="headerlink" href="#module-venv" title="Link to this heading">¶</a></h1>

  197. <div class="versionadded">

  198. <p><span class="versionmodified added">New in version 3.3.</span></p>

  199. </div>

  200. <p><strong>Source code:</strong> <a class="reference external" href="https://github.com/python/cpython/tree/3.12/Lib/venv/">Lib/venv/</a></p>

  201. <hr class="docutils" id="index-0" />

  202. <p id="venv-intro"><span id="venv-def"></span>The <code class="xref py py-mod docutils literal notranslate"><span class="pre">venv</span></code> module supports creating lightweight “virtual environments”,

  203. each with their own independent set of Python packages installed in

  204. their <a class="reference internal" href="site.html#module-site" title="site: Module responsible for site-specific configuration."><code class="xref py py-mod docutils literal notranslate"><span class="pre">site</span></code></a> directories.

  205. A virtual environment is created on top of an existing

  206. Python installation, known as the virtual environment’s “base” Python, and may

  207. optionally be isolated from the packages in the base environment,

  208. so only those explicitly installed in the virtual environment are available.</p>

  209. <p>When used from within a virtual environment, common installation tools such as

  210. <a class="reference external" href="https://pypi.org/project/pip/">pip</a> will install Python packages into a virtual environment

  211. without needing to be told to do so explicitly.</p>

  212. <p>A virtual environment is (amongst other things):</p>

  213. <ul class="simple">

  214. <li><p>Used to contain a specific Python interpreter and software libraries and

  215. binaries which are needed to support a project (library or application). These

  216. are by default isolated from software in other virtual environments and Python

  217. interpreters and libraries installed in the operating system.</p></li>

  218. <li><p>Contained in a directory, conventionally either named <code class="docutils literal notranslate"><span class="pre">venv</span></code> or <code class="docutils literal notranslate"><span class="pre">.venv</span></code> in

  219. the project directory, or under a container directory for lots of virtual

  220. environments, such as <code class="docutils literal notranslate"><span class="pre">~/.virtualenvs</span></code>.</p></li>

  221. <li><p>Not checked into source control systems such as Git.</p></li>

  222. <li><p>Considered as disposable – it should be simple to delete and recreate it from

  223. scratch. You don’t place any project code in the environment</p></li>

  224. <li><p>Not considered as movable or copyable – you just recreate the same

  225. environment in the target location.</p></li>

  226. </ul>

  227. <p>See <span class="target" id="index-1"></span><a class="pep reference external" href="https://peps.python.org/pep-0405/"><strong>PEP 405</strong></a> for more background on Python virtual environments.</p>

  228. <div class="admonition seealso">

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

  230. <p><a class="reference external" href="https://packaging.python.org/guides/installing-using-pip-and-virtual-environments/#create-and-use-virtual-environments">Python Packaging User Guide: Creating and using virtual environments</a></p>

  231. </div>

  232. <div class="availability docutils container">

  233. <p><a class="reference internal" href="intro.html#availability"><span class="std std-ref">Availability</span></a>: not Emscripten, not WASI.</p>

  234. <p>This module does not work or is not available on WebAssembly platforms

  235. <code class="docutils literal notranslate"><span class="pre">wasm32-emscripten</span></code> and <code class="docutils literal notranslate"><span class="pre">wasm32-wasi</span></code>. See

  236. <a class="reference internal" href="intro.html#wasm-availability"><span class="std std-ref">WebAssembly platforms</span></a> for more information.</p>

  237. </div>

  238. <section id="creating-virtual-environments">

  239. <h2>Creating virtual environments<a class="headerlink" href="#creating-virtual-environments" title="Link to this heading">¶</a></h2>

  240. <p>Creation of <a class="reference internal" href="#venv-def"><span class="std std-ref">virtual environments</span></a> is done by executing the

  241. command <code class="docutils literal notranslate"><span class="pre">venv</span></code>:</p>

  242. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="n">python</span> <span class="o">-</span><span class="n">m</span> <span class="n">venv</span> <span class="o">/</span><span class="n">path</span><span class="o">/</span><span class="n">to</span><span class="o">/</span><span class="n">new</span><span class="o">/</span><span class="n">virtual</span><span class="o">/</span><span class="n">environment</span>

  243. </pre></div>

  244. </div>

  245. <p>Running this command creates the target directory (creating any parent

  246. directories that don’t exist already) and places a <code class="docutils literal notranslate"><span class="pre">pyvenv.cfg</span></code> file in it

  247. with a <code class="docutils literal notranslate"><span class="pre">home</span></code> key pointing to the Python installation from which the command

  248. was run (a common name for the target directory is <code class="docutils literal notranslate"><span class="pre">.venv</span></code>).  It also creates

  249. a <code class="docutils literal notranslate"><span class="pre">bin</span></code> (or <code class="docutils literal notranslate"><span class="pre">Scripts</span></code> on Windows) subdirectory containing a copy/symlink

  250. of the Python binary/binaries (as appropriate for the platform or arguments

  251. used at environment creation time). It also creates an (initially empty)

  252. <code class="docutils literal notranslate"><span class="pre">lib/pythonX.Y/site-packages</span></code> subdirectory (on Windows, this is

  253. <code class="docutils literal notranslate"><span class="pre">Lib\site-packages</span></code>). If an existing directory is specified, it will be

  254. re-used.</p>

  255. <div class="versionchanged">

  256. <p><span class="versionmodified changed">Changed in version 3.5: </span>The use of <code class="docutils literal notranslate"><span class="pre">venv</span></code> is now recommended for creating virtual environments.</p>

  257. </div>

  258. <div class="deprecated">

  259. <p><span class="versionmodified deprecated">Deprecated since version 3.6: </span><code class="docutils literal notranslate"><span class="pre">pyvenv</span></code> was the recommended tool for creating virtual environments for

  260. Python 3.3 and 3.4, and is

  261. <a class="reference internal" href="../whatsnew/3.6.html#whatsnew36-venv"><span class="std std-ref">deprecated in Python 3.6</span></a>.</p>

  262. </div>

  263. <p>On Windows, invoke the <code class="docutils literal notranslate"><span class="pre">venv</span></code> command as follows:</p>

  264. <div class="highlight-none notranslate"><div class="highlight"><pre><span></span>c:\&gt;Python35\python -m venv c:\path\to\myenv

  265. </pre></div>

  266. </div>

  267. <p>Alternatively, if you configured the <code class="docutils literal notranslate"><span class="pre">PATH</span></code> and <code class="docutils literal notranslate"><span class="pre">PATHEXT</span></code> variables for

  268. your <a class="reference internal" href="../using/windows.html#using-on-windows"><span class="std std-ref">Python installation</span></a>:</p>

  269. <div class="highlight-none notranslate"><div class="highlight"><pre><span></span>c:\&gt;python -m venv c:\path\to\myenv

  270. </pre></div>

  271. </div>

  272. <p>The command, if run with <code class="docutils literal notranslate"><span class="pre">-h</span></code>, will show the available options:</p>

  273. <div class="highlight-none notranslate"><div class="highlight"><pre><span></span>usage: venv [-h] [--system-site-packages] [--symlinks | --copies] [--clear]

  274.             [--upgrade] [--without-pip] [--prompt PROMPT] [--upgrade-deps]

  275.             ENV_DIR [ENV_DIR ...]

  276. 

  277. Creates virtual Python environments in one or more target directories.

  278. 

  279. positional arguments:

  280.   ENV_DIR               A directory to create the environment in.

  281. 

  282. optional arguments:

  283.   -h, --help            show this help message and exit

  284.   --system-site-packages

  285.                         Give the virtual environment access to the system

  286.                         site-packages dir.

  287.   --symlinks            Try to use symlinks rather than copies, when symlinks

  288.                         are not the default for the platform.

  289.   --copies              Try to use copies rather than symlinks, even when

  290.                         symlinks are the default for the platform.

  291.   --clear               Delete the contents of the environment directory if it

  292.                         already exists, before environment creation.

  293.   --upgrade             Upgrade the environment directory to use this version

  294.                         of Python, assuming Python has been upgraded in-place.

  295.   --without-pip         Skips installing or upgrading pip in the virtual

  296.                         environment (pip is bootstrapped by default)

  297.   --prompt PROMPT       Provides an alternative prompt prefix for this

  298.                         environment.

  299.   --upgrade-deps        Upgrade core dependencies (pip) to the

  300.                         latest version in PyPI

  301. 

  302. Once an environment has been created, you may wish to activate it, e.g. by

  303. sourcing an activate script in its bin directory.

  304. </pre></div>

  305. </div>

  306. <div class="versionchanged">

  307. <p><span class="versionmodified changed">Changed in version 3.12: </span><code class="docutils literal notranslate"><span class="pre">setuptools</span></code> is no longer a core venv dependency.</p>

  308. </div>

  309. <div class="versionchanged">

  310. <p><span class="versionmodified changed">Changed in version 3.9: </span>Add <code class="docutils literal notranslate"><span class="pre">--upgrade-deps</span></code> option to upgrade pip + setuptools to the latest on PyPI</p>

  311. </div>

  312. <div class="versionchanged">

  313. <p><span class="versionmodified changed">Changed in version 3.4: </span>Installs pip by default, added the <code class="docutils literal notranslate"><span class="pre">--without-pip</span></code>  and <code class="docutils literal notranslate"><span class="pre">--copies</span></code>

  314. options</p>

  315. </div>

  316. <div class="versionchanged">

  317. <p><span class="versionmodified changed">Changed in version 3.4: </span>In earlier versions, if the target directory already existed, an error was

  318. raised, unless the <code class="docutils literal notranslate"><span class="pre">--clear</span></code> or <code class="docutils literal notranslate"><span class="pre">--upgrade</span></code> option was provided.</p>

  319. </div>

  320. <div class="admonition note">

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

  322. <p>While symlinks are supported on Windows, they are not recommended. Of

  323. particular note is that double-clicking <code class="docutils literal notranslate"><span class="pre">python.exe</span></code> in File Explorer

  324. will resolve the symlink eagerly and ignore the virtual environment.</p>

  325. </div>

  326. <div class="admonition note">

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

  328. <p>On Microsoft Windows, it may be required to enable the <code class="docutils literal notranslate"><span class="pre">Activate.ps1</span></code>

  329. script by setting the execution policy for the user. You can do this by

  330. issuing the following PowerShell command:</p>

  331. <p>PS C:&gt; Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser</p>

  332. <p>See <a class="reference external" href="https://go.microsoft.com/fwlink/?LinkID=135170">About Execution Policies</a>

  333. for more information.</p>

  334. </div>

  335. <p>The created <code class="docutils literal notranslate"><span class="pre">pyvenv.cfg</span></code> file also includes the

  336. <code class="docutils literal notranslate"><span class="pre">include-system-site-packages</span></code> key, set to <code class="docutils literal notranslate"><span class="pre">true</span></code> if <code class="docutils literal notranslate"><span class="pre">venv</span></code> is

  337. run with the <code class="docutils literal notranslate"><span class="pre">--system-site-packages</span></code> option, <code class="docutils literal notranslate"><span class="pre">false</span></code> otherwise.</p>

  338. <p>Unless the <code class="docutils literal notranslate"><span class="pre">--without-pip</span></code> option is given, <a class="reference internal" href="ensurepip.html#module-ensurepip" title="ensurepip: Bootstrapping the &quot;pip&quot; installer into an existing Python installation or virtual environment."><code class="xref py py-mod docutils literal notranslate"><span class="pre">ensurepip</span></code></a> will be

  339. invoked to bootstrap <code class="docutils literal notranslate"><span class="pre">pip</span></code> into the virtual environment.</p>

  340. <p>Multiple paths can be given to <code class="docutils literal notranslate"><span class="pre">venv</span></code>, in which case an identical virtual

  341. environment will be created, according to the given options, at each provided

  342. path.</p>

  343. </section>

  344. <section id="how-venvs-work">

  345. <span id="venv-explanation"></span><h2>How venvs work<a class="headerlink" href="#how-venvs-work" title="Link to this heading">¶</a></h2>

  346. <p>When a Python interpreter is running from a virtual environment,

  347. <a class="reference internal" href="sys.html#sys.prefix" title="sys.prefix"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.prefix</span></code></a> and <a class="reference internal" href="sys.html#sys.exec_prefix" title="sys.exec_prefix"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.exec_prefix</span></code></a>

  348. point to the directories of the virtual environment,

  349. whereas <a class="reference internal" href="sys.html#sys.base_prefix" title="sys.base_prefix"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.base_prefix</span></code></a> and <a class="reference internal" href="sys.html#sys.base_exec_prefix" title="sys.base_exec_prefix"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.base_exec_prefix</span></code></a>

  350. point to those of the base Python used to create the environment.

  351. It is sufficient to check

  352. <code class="docutils literal notranslate"><span class="pre">sys.prefix</span> <span class="pre">!=</span> <span class="pre">sys.base_prefix</span></code> to determine if the current interpreter is

  353. running from a virtual environment.</p>

  354. <p>A virtual environment may be “activated” using a script in its binary directory

  355. (<code class="docutils literal notranslate"><span class="pre">bin</span></code> on POSIX; <code class="docutils literal notranslate"><span class="pre">Scripts</span></code> on Windows).

  356. This will prepend that directory to your <span class="target" id="index-2"></span><code class="xref std std-envvar docutils literal notranslate"><span class="pre">PATH</span></code>, so that running

  357. <strong class="program">python</strong> will invoke the environment’s Python interpreter

  358. and you can run installed scripts without having to use their full path.

  359. The invocation of the activation script is platform-specific

  360. (<code class="samp docutils literal notranslate"><em><span class="pre">&lt;venv&gt;</span></em></code> must be replaced by the path to the directory

  361. containing the virtual environment):</p>

  362. <table class="docutils align-default">

  363. <thead>

  364. <tr class="row-odd"><th class="head"><p>Platform</p></th>

  365. <th class="head"><p>Shell</p></th>

  366. <th class="head"><p>Command to activate virtual environment</p></th>

  367. </tr>

  368. </thead>

  369. <tbody>

  370. <tr class="row-even"><td rowspan="4"><p>POSIX</p></td>

  371. <td><p>bash/zsh</p></td>

  372. <td><p><code class="samp docutils literal notranslate"><span class="pre">$</span> <span class="pre">source</span> <em><span class="pre">&lt;venv&gt;</span></em><span class="pre">/bin/activate</span></code></p></td>

  373. </tr>

  374. <tr class="row-odd"><td><p>fish</p></td>

  375. <td><p><code class="samp docutils literal notranslate"><span class="pre">$</span> <span class="pre">source</span> <em><span class="pre">&lt;venv&gt;</span></em><span class="pre">/bin/activate.fish</span></code></p></td>

  376. </tr>

  377. <tr class="row-even"><td><p>csh/tcsh</p></td>

  378. <td><p><code class="samp docutils literal notranslate"><span class="pre">$</span> <span class="pre">source</span> <em><span class="pre">&lt;venv&gt;</span></em><span class="pre">/bin/activate.csh</span></code></p></td>

  379. </tr>

  380. <tr class="row-odd"><td><p>PowerShell</p></td>

  381. <td><p><code class="samp docutils literal notranslate"><span class="pre">$</span> <em><span class="pre">&lt;venv&gt;</span></em><span class="pre">/bin/Activate.ps1</span></code></p></td>

  382. </tr>

  383. <tr class="row-even"><td rowspan="2"><p>Windows</p></td>

  384. <td><p>cmd.exe</p></td>

  385. <td><p><code class="samp docutils literal notranslate"><span class="pre">C:\&gt;</span> <em><span class="pre">&lt;venv&gt;</span></em><span class="pre">\Scripts\activate.bat</span></code></p></td>

  386. </tr>

  387. <tr class="row-odd"><td><p>PowerShell</p></td>

  388. <td><p><code class="samp docutils literal notranslate"><span class="pre">PS</span> <span class="pre">C:\&gt;</span> <em><span class="pre">&lt;venv&gt;</span></em><span class="pre">\Scripts\Activate.ps1</span></code></p></td>

  389. </tr>

  390. </tbody>

  391. </table>

  392. <div class="versionadded">

  393. <p><span class="versionmodified added">New in version 3.4: </span><strong class="program">fish</strong> and <strong class="program">csh</strong> activation scripts.</p>

  394. </div>

  395. <div class="versionadded">

  396. <p><span class="versionmodified added">New in version 3.8: </span>PowerShell activation scripts installed under POSIX for PowerShell Core

  397. support.</p>

  398. </div>

  399. <p>You don’t specifically <em>need</em> to activate a virtual environment,

  400. as you can just specify the full path to that environment’s

  401. Python interpreter when invoking Python.

  402. Furthermore, all scripts installed in the environment

  403. should be runnable without activating it.</p>

  404. <p>In order to achieve this, scripts installed into virtual environments have

  405. a “shebang” line which points to the environment’s Python interpreter,

  406. i.e. <code class="samp docutils literal notranslate"><span class="pre">#!/</span><em><span class="pre">&lt;path-to-venv&gt;</span></em><span class="pre">/bin/python</span></code>.

  407. This means that the script will run with that interpreter regardless of the

  408. value of <span class="target" id="index-3"></span><code class="xref std std-envvar docutils literal notranslate"><span class="pre">PATH</span></code>. On Windows, “shebang” line processing is supported if

  409. you have the <a class="reference internal" href="../using/windows.html#launcher"><span class="std std-ref">Python Launcher for Windows</span></a> installed. Thus, double-clicking an installed

  410. script in a Windows Explorer window should run it with the correct interpreter

  411. without the environment needing to be activated or on the <span class="target" id="index-4"></span><code class="xref std std-envvar docutils literal notranslate"><span class="pre">PATH</span></code>.</p>

  412. <p>When a virtual environment has been activated, the <code class="xref std std-envvar docutils literal notranslate"><span class="pre">VIRTUAL_ENV</span></code>

  413. environment variable is set to the path of the environment.

  414. Since explicitly activating a virtual environment is not required to use it,

  415. <code class="xref std std-envvar docutils literal notranslate"><span class="pre">VIRTUAL_ENV</span></code> cannot be relied upon to determine

  416. whether a virtual environment is being used.</p>

  417. <div class="admonition warning">

  418. <p class="admonition-title">Warning</p>

  419. <p>Because scripts installed in environments should not expect the

  420. environment to be activated, their shebang lines contain the absolute paths

  421. to their environment’s interpreters. Because of this, environments are

  422. inherently non-portable, in the general case. You should always have a

  423. simple means of recreating an environment (for example, if you have a

  424. requirements file <code class="docutils literal notranslate"><span class="pre">requirements.txt</span></code>, you can invoke <code class="docutils literal notranslate"><span class="pre">pip</span> <span class="pre">install</span> <span class="pre">-r</span>

  425. <span class="pre">requirements.txt</span></code> using the environment’s <code class="docutils literal notranslate"><span class="pre">pip</span></code> to install all of the

  426. packages needed by the environment). If for any reason you need to move the

  427. environment to a new location, you should recreate it at the desired

  428. location and delete the one at the old location. If you move an environment

  429. because you moved a parent directory of it, you should recreate the

  430. environment in its new location. Otherwise, software installed into the

  431. environment may not work as expected.</p>

  432. </div>

  433. <p>You can deactivate a virtual environment by typing <code class="docutils literal notranslate"><span class="pre">deactivate</span></code> in your shell.

  434. The exact mechanism is platform-specific and is an internal implementation

  435. detail (typically, a script or shell function will be used).</p>

  436. </section>

  437. <section id="api">

  438. <span id="venv-api"></span><h2>API<a class="headerlink" href="#api" title="Link to this heading">¶</a></h2>

  439. <p>The high-level method described above makes use of a simple API which provides

  440. mechanisms for third-party virtual environment creators to customize environment

  441. creation according to their needs, the <a class="reference internal" href="#venv.EnvBuilder" title="venv.EnvBuilder"><code class="xref py py-class docutils literal notranslate"><span class="pre">EnvBuilder</span></code></a> class.</p>

  442. <dl class="py class">

  443. <dt class="sig sig-object py" id="venv.EnvBuilder">

  444. <em class="property"><span class="pre">class</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">venv.</span></span><span class="sig-name descname"><span class="pre">EnvBuilder</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">system_site_packages</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="n"><span class="pre">clear</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="n"><span class="pre">symlinks</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="n"><span class="pre">upgrade</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="n"><span class="pre">with_pip</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="n"><span class="pre">prompt</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">upgrade_deps</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="#venv.EnvBuilder" title="Link to this definition">¶</a></dt>

  445. <dd><p>The <a class="reference internal" href="#venv.EnvBuilder" title="venv.EnvBuilder"><code class="xref py py-class docutils literal notranslate"><span class="pre">EnvBuilder</span></code></a> class accepts the following keyword arguments on

  446. instantiation:</p>

  447. <ul class="simple">

  448. <li><p><code class="docutils literal notranslate"><span class="pre">system_site_packages</span></code> – a Boolean value indicating that the system Python

  449. site-packages should be available to the environment (defaults to <code class="docutils literal notranslate"><span class="pre">False</span></code>).</p></li>

  450. <li><p><code class="docutils literal notranslate"><span class="pre">clear</span></code> – a Boolean value which, if true, will delete the contents of

  451. any existing target directory, before creating the environment.</p></li>

  452. <li><p><code class="docutils literal notranslate"><span class="pre">symlinks</span></code> – a Boolean value indicating whether to attempt to symlink the

  453. Python binary rather than copying.</p></li>

  454. <li><p><code class="docutils literal notranslate"><span class="pre">upgrade</span></code> – a Boolean value which, if true, will upgrade an existing

  455. environment with the running Python - for use when that Python has been

  456. upgraded in-place (defaults to <code class="docutils literal notranslate"><span class="pre">False</span></code>).</p></li>

  457. <li><p><code class="docutils literal notranslate"><span class="pre">with_pip</span></code> – a Boolean value which, if true, ensures pip is

  458. installed in the virtual environment. This uses <a class="reference internal" href="ensurepip.html#module-ensurepip" title="ensurepip: Bootstrapping the &quot;pip&quot; installer into an existing Python installation or virtual environment."><code class="xref py py-mod docutils literal notranslate"><span class="pre">ensurepip</span></code></a> with

  459. the <code class="docutils literal notranslate"><span class="pre">--default-pip</span></code> option.</p></li>

  460. <li><p><code class="docutils literal notranslate"><span class="pre">prompt</span></code> – a String to be used after virtual environment is activated

  461. (defaults to <code class="docutils literal notranslate"><span class="pre">None</span></code> which means directory name of the environment would

  462. be used). If the special string <code class="docutils literal notranslate"><span class="pre">&quot;.&quot;</span></code> is provided, the basename of the

  463. current directory is used as the prompt.</p></li>

  464. <li><p><code class="docutils literal notranslate"><span class="pre">upgrade_deps</span></code> – Update the base venv modules to the latest on PyPI</p></li>

  465. </ul>

  466. <div class="versionchanged">

  467. <p><span class="versionmodified changed">Changed in version 3.4: </span>Added the <code class="docutils literal notranslate"><span class="pre">with_pip</span></code> parameter</p>

  468. </div>

  469. <div class="versionchanged">

  470. <p><span class="versionmodified changed">Changed in version 3.6: </span>Added the <code class="docutils literal notranslate"><span class="pre">prompt</span></code> parameter</p>

  471. </div>

  472. <div class="versionchanged">

  473. <p><span class="versionmodified changed">Changed in version 3.9: </span>Added the <code class="docutils literal notranslate"><span class="pre">upgrade_deps</span></code> parameter</p>

  474. </div>

  475. <p>Creators of third-party virtual environment tools will be free to use the

  476. provided <a class="reference internal" href="#venv.EnvBuilder" title="venv.EnvBuilder"><code class="xref py py-class docutils literal notranslate"><span class="pre">EnvBuilder</span></code></a> class as a base class.</p>

  477. <p>The returned env-builder is an object which has a method, <code class="docutils literal notranslate"><span class="pre">create</span></code>:</p>

  478. <dl class="py method">

  479. <dt class="sig sig-object py" id="venv.EnvBuilder.create">

  480. <span class="sig-name descname"><span class="pre">create</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">env_dir</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#venv.EnvBuilder.create" title="Link to this definition">¶</a></dt>

  481. <dd><p>Create a virtual environment by specifying the target directory

  482. (absolute or relative to the current directory) which is to contain the

  483. virtual environment.  The <code class="docutils literal notranslate"><span class="pre">create</span></code> method will either create the

  484. environment in the specified directory, or raise an appropriate

  485. exception.</p>

  486. <p>The <code class="docutils literal notranslate"><span class="pre">create</span></code> method of the <a class="reference internal" href="#venv.EnvBuilder" title="venv.EnvBuilder"><code class="xref py py-class docutils literal notranslate"><span class="pre">EnvBuilder</span></code></a> class illustrates the

  487. hooks available for subclass customization:</p>

  488. <div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">create</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">env_dir</span><span class="p">):</span>

  489. <span class="w">    </span><span class="sd">&quot;&quot;&quot;</span>

  490. <span class="sd">    Create a virtualized Python environment in a directory.</span>

  491. <span class="sd">    env_dir is the target directory to create an environment in.</span>

  492. <span class="sd">    &quot;&quot;&quot;</span>

  493.     <span class="n">env_dir</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">abspath</span><span class="p">(</span><span class="n">env_dir</span><span class="p">)</span>

  494.     <span class="n">context</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">ensure_directories</span><span class="p">(</span><span class="n">env_dir</span><span class="p">)</span>

  495.     <span class="bp">self</span><span class="o">.</span><span class="n">create_configuration</span><span class="p">(</span><span class="n">context</span><span class="p">)</span>

  496.     <span class="bp">self</span><span class="o">.</span><span class="n">setup_python</span><span class="p">(</span><span class="n">context</span><span class="p">)</span>

  497.     <span class="bp">self</span><span class="o">.</span><span class="n">setup_scripts</span><span class="p">(</span><span class="n">context</span><span class="p">)</span>

  498.     <span class="bp">self</span><span class="o">.</span><span class="n">post_setup</span><span class="p">(</span><span class="n">context</span><span class="p">)</span>

  499. </pre></div>

  500. </div>

  501. <p>Each of the methods <a class="reference internal" href="#venv.EnvBuilder.ensure_directories" title="venv.EnvBuilder.ensure_directories"><code class="xref py py-meth docutils literal notranslate"><span class="pre">ensure_directories()</span></code></a>,

  502. <a class="reference internal" href="#venv.EnvBuilder.create_configuration" title="venv.EnvBuilder.create_configuration"><code class="xref py py-meth docutils literal notranslate"><span class="pre">create_configuration()</span></code></a>, <a class="reference internal" href="#venv.EnvBuilder.setup_python" title="venv.EnvBuilder.setup_python"><code class="xref py py-meth docutils literal notranslate"><span class="pre">setup_python()</span></code></a>,

  503. <a class="reference internal" href="#venv.EnvBuilder.setup_scripts" title="venv.EnvBuilder.setup_scripts"><code class="xref py py-meth docutils literal notranslate"><span class="pre">setup_scripts()</span></code></a> and <a class="reference internal" href="#venv.EnvBuilder.post_setup" title="venv.EnvBuilder.post_setup"><code class="xref py py-meth docutils literal notranslate"><span class="pre">post_setup()</span></code></a> can be overridden.</p>

  504. </dd></dl>

  505. 

  506. <dl class="py method">

  507. <dt class="sig sig-object py" id="venv.EnvBuilder.ensure_directories">

  508. <span class="sig-name descname"><span class="pre">ensure_directories</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">env_dir</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#venv.EnvBuilder.ensure_directories" title="Link to this definition">¶</a></dt>

  509. <dd><p>Creates the environment directory and all necessary subdirectories that

  510. don’t already exist, and returns a context object.  This context object

  511. is just a holder for attributes (such as paths) for use by the other

  512. methods.  If the <a class="reference internal" href="#venv.EnvBuilder" title="venv.EnvBuilder"><code class="xref py py-class docutils literal notranslate"><span class="pre">EnvBuilder</span></code></a> is created with the arg

  513. <code class="docutils literal notranslate"><span class="pre">clear=True</span></code>, contents of the environment directory will be cleared

  514. and then all necessary subdirectories will be recreated.</p>

  515. <p>The returned context object is a <a class="reference internal" href="types.html#types.SimpleNamespace" title="types.SimpleNamespace"><code class="xref py py-class docutils literal notranslate"><span class="pre">types.SimpleNamespace</span></code></a> with the

  516. following attributes:</p>

  517. <ul class="simple">

  518. <li><p><code class="docutils literal notranslate"><span class="pre">env_dir</span></code> - The location of the virtual environment. Used for

  519. <code class="docutils literal notranslate"><span class="pre">__VENV_DIR__</span></code> in activation scripts (see <a class="reference internal" href="#venv.EnvBuilder.install_scripts" title="venv.EnvBuilder.install_scripts"><code class="xref py py-meth docutils literal notranslate"><span class="pre">install_scripts()</span></code></a>).</p></li>

  520. <li><p><code class="docutils literal notranslate"><span class="pre">env_name</span></code> - The name of the virtual environment. Used for

  521. <code class="docutils literal notranslate"><span class="pre">__VENV_NAME__</span></code> in activation scripts (see <a class="reference internal" href="#venv.EnvBuilder.install_scripts" title="venv.EnvBuilder.install_scripts"><code class="xref py py-meth docutils literal notranslate"><span class="pre">install_scripts()</span></code></a>).</p></li>

  522. <li><p><code class="docutils literal notranslate"><span class="pre">prompt</span></code> - The prompt to be used by the activation scripts. Used for

  523. <code class="docutils literal notranslate"><span class="pre">__VENV_PROMPT__</span></code> in activation scripts (see <a class="reference internal" href="#venv.EnvBuilder.install_scripts" title="venv.EnvBuilder.install_scripts"><code class="xref py py-meth docutils literal notranslate"><span class="pre">install_scripts()</span></code></a>).</p></li>

  524. <li><p><code class="docutils literal notranslate"><span class="pre">executable</span></code> - The underlying Python executable used by the virtual

  525. environment. This takes into account the case where a virtual environment

  526. is created from another virtual environment.</p></li>

  527. <li><p><code class="docutils literal notranslate"><span class="pre">inc_path</span></code> - The include path for the virtual environment.</p></li>

  528. <li><p><code class="docutils literal notranslate"><span class="pre">lib_path</span></code> - The purelib path for the virtual environment.</p></li>

  529. <li><p><code class="docutils literal notranslate"><span class="pre">bin_path</span></code> - The script path for the virtual environment.</p></li>

  530. <li><p><code class="docutils literal notranslate"><span class="pre">bin_name</span></code> - The name of the script path relative to the virtual

  531. environment location. Used for <code class="docutils literal notranslate"><span class="pre">__VENV_BIN_NAME__</span></code> in activation

  532. scripts (see <a class="reference internal" href="#venv.EnvBuilder.install_scripts" title="venv.EnvBuilder.install_scripts"><code class="xref py py-meth docutils literal notranslate"><span class="pre">install_scripts()</span></code></a>).</p></li>

  533. <li><p><code class="docutils literal notranslate"><span class="pre">env_exe</span></code> - The name of the Python interpreter in the virtual

  534. environment. Used for <code class="docutils literal notranslate"><span class="pre">__VENV_PYTHON__</span></code> in activation scripts

  535. (see <a class="reference internal" href="#venv.EnvBuilder.install_scripts" title="venv.EnvBuilder.install_scripts"><code class="xref py py-meth docutils literal notranslate"><span class="pre">install_scripts()</span></code></a>).</p></li>

  536. <li><p><code class="docutils literal notranslate"><span class="pre">env_exec_cmd</span></code> - The name of the Python interpreter, taking into

  537. account filesystem redirections. This can be used to run Python in

  538. the virtual environment.</p></li>

  539. </ul>

  540. <div class="versionchanged">

  541. <p><span class="versionmodified changed">Changed in version 3.11: </span>The <em>venv</em>

  542. <a class="reference internal" href="sysconfig.html#installation-paths"><span class="std std-ref">sysconfig installation scheme</span></a>

  543. is used to construct the paths of the created directories.</p>

  544. </div>

  545. <div class="versionchanged">

  546. <p><span class="versionmodified changed">Changed in version 3.12: </span>The attribute <code class="docutils literal notranslate"><span class="pre">lib_path</span></code> was added to the context, and the context

  547. object was documented.</p>

  548. </div>

  549. </dd></dl>

  550. 

  551. <dl class="py method">

  552. <dt class="sig sig-object py" id="venv.EnvBuilder.create_configuration">

  553. <span class="sig-name descname"><span class="pre">create_configuration</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">context</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#venv.EnvBuilder.create_configuration" title="Link to this definition">¶</a></dt>

  554. <dd><p>Creates the <code class="docutils literal notranslate"><span class="pre">pyvenv.cfg</span></code> configuration file in the environment.</p>

  555. </dd></dl>

  556. 

  557. <dl class="py method">

  558. <dt class="sig sig-object py" id="venv.EnvBuilder.setup_python">

  559. <span class="sig-name descname"><span class="pre">setup_python</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">context</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#venv.EnvBuilder.setup_python" title="Link to this definition">¶</a></dt>

  560. <dd><p>Creates a copy or symlink to the Python executable in the environment.

  561. On POSIX systems, if a specific executable <code class="docutils literal notranslate"><span class="pre">python3.x</span></code> was used,

  562. symlinks to <code class="docutils literal notranslate"><span class="pre">python</span></code> and <code class="docutils literal notranslate"><span class="pre">python3</span></code> will be created pointing to that

  563. executable, unless files with those names already exist.</p>

  564. </dd></dl>

  565. 

  566. <dl class="py method">

  567. <dt class="sig sig-object py" id="venv.EnvBuilder.setup_scripts">

  568. <span class="sig-name descname"><span class="pre">setup_scripts</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">context</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#venv.EnvBuilder.setup_scripts" title="Link to this definition">¶</a></dt>

  569. <dd><p>Installs activation scripts appropriate to the platform into the virtual

  570. environment.</p>

  571. </dd></dl>

  572. 

  573. <dl class="py method">

  574. <dt class="sig sig-object py" id="venv.EnvBuilder.upgrade_dependencies">

  575. <span class="sig-name descname"><span class="pre">upgrade_dependencies</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">context</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#venv.EnvBuilder.upgrade_dependencies" title="Link to this definition">¶</a></dt>

  576. <dd><p>Upgrades the core venv dependency packages (currently <code class="docutils literal notranslate"><span class="pre">pip</span></code>)

  577. in the environment. This is done by shelling out to the

  578. <code class="docutils literal notranslate"><span class="pre">pip</span></code> executable in the environment.</p>

  579. <div class="versionadded">

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

  581. </div>

  582. <div class="versionchanged">

  583. <p><span class="versionmodified changed">Changed in version 3.12: </span><code class="docutils literal notranslate"><span class="pre">setuptools</span></code> is no longer a core venv dependency.</p>

  584. </div>

  585. </dd></dl>

  586. 

  587. <dl class="py method">

  588. <dt class="sig sig-object py" id="venv.EnvBuilder.post_setup">

  589. <span class="sig-name descname"><span class="pre">post_setup</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">context</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#venv.EnvBuilder.post_setup" title="Link to this definition">¶</a></dt>

  590. <dd><p>A placeholder method which can be overridden in third party

  591. implementations to pre-install packages in the virtual environment or

  592. perform other post-creation steps.</p>

  593. </dd></dl>

  594. 

  595. <div class="versionchanged">

  596. <p><span class="versionmodified changed">Changed in version 3.7.2: </span>Windows now uses redirector scripts for <code class="docutils literal notranslate"><span class="pre">python[w].exe</span></code> instead of

  597. copying the actual binaries. In 3.7.2 only <a class="reference internal" href="#venv.EnvBuilder.setup_python" title="venv.EnvBuilder.setup_python"><code class="xref py py-meth docutils literal notranslate"><span class="pre">setup_python()</span></code></a> does

  598. nothing unless running from a build in the source tree.</p>

  599. </div>

  600. <div class="versionchanged">

  601. <p><span class="versionmodified changed">Changed in version 3.7.3: </span>Windows copies the redirector scripts as part of <a class="reference internal" href="#venv.EnvBuilder.setup_python" title="venv.EnvBuilder.setup_python"><code class="xref py py-meth docutils literal notranslate"><span class="pre">setup_python()</span></code></a>

  602. instead of <a class="reference internal" href="#venv.EnvBuilder.setup_scripts" title="venv.EnvBuilder.setup_scripts"><code class="xref py py-meth docutils literal notranslate"><span class="pre">setup_scripts()</span></code></a>. This was not the case in 3.7.2.

  603. When using symlinks, the original executables will be linked.</p>

  604. </div>

  605. <p>In addition, <a class="reference internal" href="#venv.EnvBuilder" title="venv.EnvBuilder"><code class="xref py py-class docutils literal notranslate"><span class="pre">EnvBuilder</span></code></a> provides this utility method that can be

  606. called from <a class="reference internal" href="#venv.EnvBuilder.setup_scripts" title="venv.EnvBuilder.setup_scripts"><code class="xref py py-meth docutils literal notranslate"><span class="pre">setup_scripts()</span></code></a> or <a class="reference internal" href="#venv.EnvBuilder.post_setup" title="venv.EnvBuilder.post_setup"><code class="xref py py-meth docutils literal notranslate"><span class="pre">post_setup()</span></code></a> in subclasses to

  607. assist in installing custom scripts into the virtual environment.</p>

  608. <dl class="py method">

  609. <dt class="sig sig-object py" id="venv.EnvBuilder.install_scripts">

  610. <span class="sig-name descname"><span class="pre">install_scripts</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">context</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">path</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#venv.EnvBuilder.install_scripts" title="Link to this definition">¶</a></dt>

  611. <dd><p><em>path</em> is the path to a directory that should contain subdirectories

  612. “common”, “posix”, “nt”, each containing scripts destined for the bin

  613. directory in the environment.  The contents of “common” and the

  614. directory corresponding to <a class="reference internal" href="os.html#os.name" title="os.name"><code class="xref py py-data docutils literal notranslate"><span class="pre">os.name</span></code></a> are copied after some text

  615. replacement of placeholders:</p>

  616. <ul class="simple">

  617. <li><p><code class="docutils literal notranslate"><span class="pre">__VENV_DIR__</span></code> is replaced with the absolute path of the environment

  618. directory.</p></li>

  619. <li><p><code class="docutils literal notranslate"><span class="pre">__VENV_NAME__</span></code> is replaced with the environment name (final path

  620. segment of environment directory).</p></li>

  621. <li><p><code class="docutils literal notranslate"><span class="pre">__VENV_PROMPT__</span></code> is replaced with the prompt (the environment

  622. name surrounded by parentheses and with a following space)</p></li>

  623. <li><p><code class="docutils literal notranslate"><span class="pre">__VENV_BIN_NAME__</span></code> is replaced with the name of the bin directory

  624. (either <code class="docutils literal notranslate"><span class="pre">bin</span></code> or <code class="docutils literal notranslate"><span class="pre">Scripts</span></code>).</p></li>

  625. <li><p><code class="docutils literal notranslate"><span class="pre">__VENV_PYTHON__</span></code> is replaced with the absolute path of the

  626. environment’s executable.</p></li>

  627. </ul>

  628. <p>The directories are allowed to exist (for when an existing environment

  629. is being upgraded).</p>

  630. </dd></dl>

  631. 

  632. </dd></dl>

  633. 

  634. <p>There is also a module-level convenience function:</p>

  635. <dl class="py function">

  636. <dt class="sig sig-object py" id="venv.create">

  637. <span class="sig-prename descclassname"><span class="pre">venv.</span></span><span class="sig-name descname"><span class="pre">create</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">env_dir</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">system_site_packages</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="n"><span class="pre">clear</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="n"><span class="pre">symlinks</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="n"><span class="pre">with_pip</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="n"><span class="pre">prompt</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">upgrade_deps</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="#venv.create" title="Link to this definition">¶</a></dt>

  638. <dd><p>Create an <a class="reference internal" href="#venv.EnvBuilder" title="venv.EnvBuilder"><code class="xref py py-class docutils literal notranslate"><span class="pre">EnvBuilder</span></code></a> with the given keyword arguments, and call its

  639. <a class="reference internal" href="#venv.EnvBuilder.create" title="venv.EnvBuilder.create"><code class="xref py py-meth docutils literal notranslate"><span class="pre">create()</span></code></a> method with the <em>env_dir</em> argument.</p>

  640. <div class="versionadded">

  641. <p><span class="versionmodified added">New in version 3.3.</span></p>

  642. </div>

  643. <div class="versionchanged">

  644. <p><span class="versionmodified changed">Changed in version 3.4: </span>Added the <code class="docutils literal notranslate"><span class="pre">with_pip</span></code> parameter</p>

  645. </div>

  646. <div class="versionchanged">

  647. <p><span class="versionmodified changed">Changed in version 3.6: </span>Added the <code class="docutils literal notranslate"><span class="pre">prompt</span></code> parameter</p>

  648. </div>

  649. <div class="versionchanged">

  650. <p><span class="versionmodified changed">Changed in version 3.9: </span>Added the <code class="docutils literal notranslate"><span class="pre">upgrade_deps</span></code> parameter</p>

  651. </div>

  652. </dd></dl>

  653. 

  654. </section>

  655. <section id="an-example-of-extending-envbuilder">

  656. <h2>An example of extending <code class="docutils literal notranslate"><span class="pre">EnvBuilder</span></code><a class="headerlink" href="#an-example-of-extending-envbuilder" title="Link to this heading">¶</a></h2>

  657. <p>The following script shows how to extend <a class="reference internal" href="#venv.EnvBuilder" title="venv.EnvBuilder"><code class="xref py py-class docutils literal notranslate"><span class="pre">EnvBuilder</span></code></a> by implementing a

  658. subclass which installs setuptools and pip into a created virtual environment:</p>

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

  660. <span class="kn">import</span> <span class="nn">os.path</span>

  661. <span class="kn">from</span> <span class="nn">subprocess</span> <span class="kn">import</span> <span class="n">Popen</span><span class="p">,</span> <span class="n">PIPE</span>

  662. <span class="kn">import</span> <span class="nn">sys</span>

  663. <span class="kn">from</span> <span class="nn">threading</span> <span class="kn">import</span> <span class="n">Thread</span>

  664. <span class="kn">from</span> <span class="nn">urllib.parse</span> <span class="kn">import</span> <span class="n">urlparse</span>

  665. <span class="kn">from</span> <span class="nn">urllib.request</span> <span class="kn">import</span> <span class="n">urlretrieve</span>

  666. <span class="kn">import</span> <span class="nn">venv</span>

  667. 

  668. <span class="k">class</span> <span class="nc">ExtendedEnvBuilder</span><span class="p">(</span><span class="n">venv</span><span class="o">.</span><span class="n">EnvBuilder</span><span class="p">):</span>

  669. <span class="w">    </span><span class="sd">&quot;&quot;&quot;</span>

  670. <span class="sd">    This builder installs setuptools and pip so that you can pip or</span>

  671. <span class="sd">    easy_install other packages into the created virtual environment.</span>

  672. 

  673. <span class="sd">    :param nodist: If true, setuptools and pip are not installed into the</span>

  674. <span class="sd">                   created virtual environment.</span>

  675. <span class="sd">    :param nopip: If true, pip is not installed into the created</span>

  676. <span class="sd">                  virtual environment.</span>

  677. <span class="sd">    :param progress: If setuptools or pip are installed, the progress of the</span>

  678. <span class="sd">                     installation can be monitored by passing a progress</span>

  679. <span class="sd">                     callable. If specified, it is called with two</span>

  680. <span class="sd">                     arguments: a string indicating some progress, and a</span>

  681. <span class="sd">                     context indicating where the string is coming from.</span>

  682. <span class="sd">                     The context argument can have one of three values:</span>

  683. <span class="sd">                     &#39;main&#39;, indicating that it is called from virtualize()</span>

  684. <span class="sd">                     itself, and &#39;stdout&#39; and &#39;stderr&#39;, which are obtained</span>

  685. <span class="sd">                     by reading lines from the output streams of a subprocess</span>

  686. <span class="sd">                     which is used to install the app.</span>

  687. 

  688. <span class="sd">                     If a callable is not specified, default progress</span>

  689. <span class="sd">                     information is output to sys.stderr.</span>

  690. <span class="sd">    &quot;&quot;&quot;</span>

  691. 

  692.     <span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">args</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>

  693.         <span class="bp">self</span><span class="o">.</span><span class="n">nodist</span> <span class="o">=</span> <span class="n">kwargs</span><span class="o">.</span><span class="n">pop</span><span class="p">(</span><span class="s1">&#39;nodist&#39;</span><span class="p">,</span> <span class="kc">False</span><span class="p">)</span>

  694.         <span class="bp">self</span><span class="o">.</span><span class="n">nopip</span> <span class="o">=</span> <span class="n">kwargs</span><span class="o">.</span><span class="n">pop</span><span class="p">(</span><span class="s1">&#39;nopip&#39;</span><span class="p">,</span> <span class="kc">False</span><span class="p">)</span>

  695.         <span class="bp">self</span><span class="o">.</span><span class="n">progress</span> <span class="o">=</span> <span class="n">kwargs</span><span class="o">.</span><span class="n">pop</span><span class="p">(</span><span class="s1">&#39;progress&#39;</span><span class="p">,</span> <span class="kc">None</span><span class="p">)</span>

  696.         <span class="bp">self</span><span class="o">.</span><span class="n">verbose</span> <span class="o">=</span> <span class="n">kwargs</span><span class="o">.</span><span class="n">pop</span><span class="p">(</span><span class="s1">&#39;verbose&#39;</span><span class="p">,</span> <span class="kc">False</span><span class="p">)</span>

  697.         <span class="nb">super</span><span class="p">()</span><span class="o">.</span><span class="fm">__init__</span><span class="p">(</span><span class="o">*</span><span class="n">args</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">)</span>

  698. 

  699.     <span class="k">def</span> <span class="nf">post_setup</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">context</span><span class="p">):</span>

  700. <span class="w">        </span><span class="sd">&quot;&quot;&quot;</span>

  701. <span class="sd">        Set up any packages which need to be pre-installed into the</span>

  702. <span class="sd">        virtual environment being created.</span>

  703. 

  704. <span class="sd">        :param context: The information for the virtual environment</span>

  705. <span class="sd">                        creation request being processed.</span>

  706. <span class="sd">        &quot;&quot;&quot;</span>

  707.         <span class="n">os</span><span class="o">.</span><span class="n">environ</span><span class="p">[</span><span class="s1">&#39;VIRTUAL_ENV&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="n">context</span><span class="o">.</span><span class="n">env_dir</span>

  708.         <span class="k">if</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">nodist</span><span class="p">:</span>

  709.             <span class="bp">self</span><span class="o">.</span><span class="n">install_setuptools</span><span class="p">(</span><span class="n">context</span><span class="p">)</span>

  710.         <span class="c1"># Can&#39;t install pip without setuptools</span>

  711.         <span class="k">if</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">nopip</span> <span class="ow">and</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">nodist</span><span class="p">:</span>

  712.             <span class="bp">self</span><span class="o">.</span><span class="n">install_pip</span><span class="p">(</span><span class="n">context</span><span class="p">)</span>

  713. 

  714.     <span class="k">def</span> <span class="nf">reader</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">stream</span><span class="p">,</span> <span class="n">context</span><span class="p">):</span>

  715. <span class="w">        </span><span class="sd">&quot;&quot;&quot;</span>

  716. <span class="sd">        Read lines from a subprocess&#39; output stream and either pass to a progress</span>

  717. <span class="sd">        callable (if specified) or write progress information to sys.stderr.</span>

  718. <span class="sd">        &quot;&quot;&quot;</span>

  719.         <span class="n">progress</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">progress</span>

  720.         <span class="k">while</span> <span class="kc">True</span><span class="p">:</span>

  721.             <span class="n">s</span> <span class="o">=</span> <span class="n">stream</span><span class="o">.</span><span class="n">readline</span><span class="p">()</span>

  722.             <span class="k">if</span> <span class="ow">not</span> <span class="n">s</span><span class="p">:</span>

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

  724.             <span class="k">if</span> <span class="n">progress</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>

  725.                 <span class="n">progress</span><span class="p">(</span><span class="n">s</span><span class="p">,</span> <span class="n">context</span><span class="p">)</span>

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

  727.                 <span class="k">if</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">verbose</span><span class="p">:</span>

  728.                     <span class="n">sys</span><span class="o">.</span><span class="n">stderr</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="s1">&#39;.&#39;</span><span class="p">)</span>

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

  730.                     <span class="n">sys</span><span class="o">.</span><span class="n">stderr</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="n">s</span><span class="o">.</span><span class="n">decode</span><span class="p">(</span><span class="s1">&#39;utf-8&#39;</span><span class="p">))</span>

  731.                 <span class="n">sys</span><span class="o">.</span><span class="n">stderr</span><span class="o">.</span><span class="n">flush</span><span class="p">()</span>

  732.         <span class="n">stream</span><span class="o">.</span><span class="n">close</span><span class="p">()</span>

  733. 

  734.     <span class="k">def</span> <span class="nf">install_script</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">context</span><span class="p">,</span> <span class="n">name</span><span class="p">,</span> <span class="n">url</span><span class="p">):</span>

  735.         <span class="n">_</span><span class="p">,</span> <span class="n">_</span><span class="p">,</span> <span class="n">path</span><span class="p">,</span> <span class="n">_</span><span class="p">,</span> <span class="n">_</span><span class="p">,</span> <span class="n">_</span> <span class="o">=</span> <span class="n">urlparse</span><span class="p">(</span><span class="n">url</span><span class="p">)</span>

  736.         <span class="n">fn</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">split</span><span class="p">(</span><span class="n">path</span><span class="p">)[</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span>

  737.         <span class="n">binpath</span> <span class="o">=</span> <span class="n">context</span><span class="o">.</span><span class="n">bin_path</span>

  738.         <span class="n">distpath</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="n">binpath</span><span class="p">,</span> <span class="n">fn</span><span class="p">)</span>

  739.         <span class="c1"># Download script into the virtual environment&#39;s binaries folder</span>

  740.         <span class="n">urlretrieve</span><span class="p">(</span><span class="n">url</span><span class="p">,</span> <span class="n">distpath</span><span class="p">)</span>

  741.         <span class="n">progress</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">progress</span>

  742.         <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">verbose</span><span class="p">:</span>

  743.             <span class="n">term</span> <span class="o">=</span> <span class="s1">&#39;</span><span class="se">\n</span><span class="s1">&#39;</span>

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

  745.             <span class="n">term</span> <span class="o">=</span> <span class="s1">&#39;&#39;</span>

  746.         <span class="k">if</span> <span class="n">progress</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>

  747.             <span class="n">progress</span><span class="p">(</span><span class="s1">&#39;Installing </span><span class="si">%s</span><span class="s1"> ...</span><span class="si">%s</span><span class="s1">&#39;</span> <span class="o">%</span> <span class="p">(</span><span class="n">name</span><span class="p">,</span> <span class="n">term</span><span class="p">),</span> <span class="s1">&#39;main&#39;</span><span class="p">)</span>

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

  749.             <span class="n">sys</span><span class="o">.</span><span class="n">stderr</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="s1">&#39;Installing </span><span class="si">%s</span><span class="s1"> ...</span><span class="si">%s</span><span class="s1">&#39;</span> <span class="o">%</span> <span class="p">(</span><span class="n">name</span><span class="p">,</span> <span class="n">term</span><span class="p">))</span>

  750.             <span class="n">sys</span><span class="o">.</span><span class="n">stderr</span><span class="o">.</span><span class="n">flush</span><span class="p">()</span>

  751.         <span class="c1"># Install in the virtual environment</span>

  752.         <span class="n">args</span> <span class="o">=</span> <span class="p">[</span><span class="n">context</span><span class="o">.</span><span class="n">env_exe</span><span class="p">,</span> <span class="n">fn</span><span class="p">]</span>

  753.         <span class="n">p</span> <span class="o">=</span> <span class="n">Popen</span><span class="p">(</span><span class="n">args</span><span class="p">,</span> <span class="n">stdout</span><span class="o">=</span><span class="n">PIPE</span><span class="p">,</span> <span class="n">stderr</span><span class="o">=</span><span class="n">PIPE</span><span class="p">,</span> <span class="n">cwd</span><span class="o">=</span><span class="n">binpath</span><span class="p">)</span>

  754.         <span class="n">t1</span> <span class="o">=</span> <span class="n">Thread</span><span class="p">(</span><span class="n">target</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">reader</span><span class="p">,</span> <span class="n">args</span><span class="o">=</span><span class="p">(</span><span class="n">p</span><span class="o">.</span><span class="n">stdout</span><span class="p">,</span> <span class="s1">&#39;stdout&#39;</span><span class="p">))</span>

  755.         <span class="n">t1</span><span class="o">.</span><span class="n">start</span><span class="p">()</span>

  756.         <span class="n">t2</span> <span class="o">=</span> <span class="n">Thread</span><span class="p">(</span><span class="n">target</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">reader</span><span class="p">,</span> <span class="n">args</span><span class="o">=</span><span class="p">(</span><span class="n">p</span><span class="o">.</span><span class="n">stderr</span><span class="p">,</span> <span class="s1">&#39;stderr&#39;</span><span class="p">))</span>

  757.         <span class="n">t2</span><span class="o">.</span><span class="n">start</span><span class="p">()</span>

  758.         <span class="n">p</span><span class="o">.</span><span class="n">wait</span><span class="p">()</span>

  759.         <span class="n">t1</span><span class="o">.</span><span class="n">join</span><span class="p">()</span>

  760.         <span class="n">t2</span><span class="o">.</span><span class="n">join</span><span class="p">()</span>

  761.         <span class="k">if</span> <span class="n">progress</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>

  762.             <span class="n">progress</span><span class="p">(</span><span class="s1">&#39;done.&#39;</span><span class="p">,</span> <span class="s1">&#39;main&#39;</span><span class="p">)</span>

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

  764.             <span class="n">sys</span><span class="o">.</span><span class="n">stderr</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="s1">&#39;done.</span><span class="se">\n</span><span class="s1">&#39;</span><span class="p">)</span>

  765.         <span class="c1"># Clean up - no longer needed</span>

  766.         <span class="n">os</span><span class="o">.</span><span class="n">unlink</span><span class="p">(</span><span class="n">distpath</span><span class="p">)</span>

  767. 

  768.     <span class="k">def</span> <span class="nf">install_setuptools</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">context</span><span class="p">):</span>

  769. <span class="w">        </span><span class="sd">&quot;&quot;&quot;</span>

  770. <span class="sd">        Install setuptools in the virtual environment.</span>

  771. 

  772. <span class="sd">        :param context: The information for the virtual environment</span>

  773. <span class="sd">                        creation request being processed.</span>

  774. <span class="sd">        &quot;&quot;&quot;</span>

  775.         <span class="n">url</span> <span class="o">=</span> <span class="s2">&quot;https://bootstrap.pypa.io/ez_setup.py&quot;</span>

  776.         <span class="bp">self</span><span class="o">.</span><span class="n">install_script</span><span class="p">(</span><span class="n">context</span><span class="p">,</span> <span class="s1">&#39;setuptools&#39;</span><span class="p">,</span> <span class="n">url</span><span class="p">)</span>

  777.         <span class="c1"># clear up the setuptools archive which gets downloaded</span>

  778.         <span class="n">pred</span> <span class="o">=</span> <span class="k">lambda</span> <span class="n">o</span><span class="p">:</span> <span class="n">o</span><span class="o">.</span><span class="n">startswith</span><span class="p">(</span><span class="s1">&#39;setuptools-&#39;</span><span class="p">)</span> <span class="ow">and</span> <span class="n">o</span><span class="o">.</span><span class="n">endswith</span><span class="p">(</span><span class="s1">&#39;.tar.gz&#39;</span><span class="p">)</span>

  779.         <span class="n">files</span> <span class="o">=</span> <span class="nb">filter</span><span class="p">(</span><span class="n">pred</span><span class="p">,</span> <span class="n">os</span><span class="o">.</span><span class="n">listdir</span><span class="p">(</span><span class="n">context</span><span class="o">.</span><span class="n">bin_path</span><span class="p">))</span>

  780.         <span class="k">for</span> <span class="n">f</span> <span class="ow">in</span> <span class="n">files</span><span class="p">:</span>

  781.             <span class="n">f</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="n">context</span><span class="o">.</span><span class="n">bin_path</span><span class="p">,</span> <span class="n">f</span><span class="p">)</span>

  782.             <span class="n">os</span><span class="o">.</span><span class="n">unlink</span><span class="p">(</span><span class="n">f</span><span class="p">)</span>

  783. 

  784.     <span class="k">def</span> <span class="nf">install_pip</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">context</span><span class="p">):</span>

  785. <span class="w">        </span><span class="sd">&quot;&quot;&quot;</span>

  786. <span class="sd">        Install pip in the virtual environment.</span>

  787. 

  788. <span class="sd">        :param context: The information for the virtual environment</span>

  789. <span class="sd">                        creation request being processed.</span>

  790. <span class="sd">        &quot;&quot;&quot;</span>

  791.         <span class="n">url</span> <span class="o">=</span> <span class="s1">&#39;https://bootstrap.pypa.io/get-pip.py&#39;</span>

  792.         <span class="bp">self</span><span class="o">.</span><span class="n">install_script</span><span class="p">(</span><span class="n">context</span><span class="p">,</span> <span class="s1">&#39;pip&#39;</span><span class="p">,</span> <span class="n">url</span><span class="p">)</span>

  793. 

  794. 

  795. <span class="k">def</span> <span class="nf">main</span><span class="p">(</span><span class="n">args</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span>

  796.     <span class="kn">import</span> <span class="nn">argparse</span>

  797. 

  798.     <span class="n">parser</span> <span class="o">=</span> <span class="n">argparse</span><span class="o">.</span><span class="n">ArgumentParser</span><span class="p">(</span><span class="n">prog</span><span class="o">=</span><span class="vm">__name__</span><span class="p">,</span>

  799.                                      <span class="n">description</span><span class="o">=</span><span class="s1">&#39;Creates virtual Python &#39;</span>

  800.                                                  <span class="s1">&#39;environments in one or &#39;</span>

  801.                                                  <span class="s1">&#39;more target &#39;</span>

  802.                                                  <span class="s1">&#39;directories.&#39;</span><span class="p">)</span>

  803.     <span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s1">&#39;dirs&#39;</span><span class="p">,</span> <span class="n">metavar</span><span class="o">=</span><span class="s1">&#39;ENV_DIR&#39;</span><span class="p">,</span> <span class="n">nargs</span><span class="o">=</span><span class="s1">&#39;+&#39;</span><span class="p">,</span>

  804.                         <span class="n">help</span><span class="o">=</span><span class="s1">&#39;A directory in which to create the &#39;</span>

  805.                              <span class="s1">&#39;virtual environment.&#39;</span><span class="p">)</span>

  806.     <span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s1">&#39;--no-setuptools&#39;</span><span class="p">,</span> <span class="n">default</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span>

  807.                         <span class="n">action</span><span class="o">=</span><span class="s1">&#39;store_true&#39;</span><span class="p">,</span> <span class="n">dest</span><span class="o">=</span><span class="s1">&#39;nodist&#39;</span><span class="p">,</span>

  808.                         <span class="n">help</span><span class="o">=</span><span class="s2">&quot;Don&#39;t install setuptools or pip in the &quot;</span>

  809.                              <span class="s2">&quot;virtual environment.&quot;</span><span class="p">)</span>

  810.     <span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s1">&#39;--no-pip&#39;</span><span class="p">,</span> <span class="n">default</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span>

  811.                         <span class="n">action</span><span class="o">=</span><span class="s1">&#39;store_true&#39;</span><span class="p">,</span> <span class="n">dest</span><span class="o">=</span><span class="s1">&#39;nopip&#39;</span><span class="p">,</span>

  812.                         <span class="n">help</span><span class="o">=</span><span class="s2">&quot;Don&#39;t install pip in the virtual &quot;</span>

  813.                              <span class="s2">&quot;environment.&quot;</span><span class="p">)</span>

  814.     <span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s1">&#39;--system-site-packages&#39;</span><span class="p">,</span> <span class="n">default</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span>

  815.                         <span class="n">action</span><span class="o">=</span><span class="s1">&#39;store_true&#39;</span><span class="p">,</span> <span class="n">dest</span><span class="o">=</span><span class="s1">&#39;system_site&#39;</span><span class="p">,</span>

  816.                         <span class="n">help</span><span class="o">=</span><span class="s1">&#39;Give the virtual environment access to the &#39;</span>

  817.                              <span class="s1">&#39;system site-packages dir.&#39;</span><span class="p">)</span>

  818.     <span class="k">if</span> <span class="n">os</span><span class="o">.</span><span class="n">name</span> <span class="o">==</span> <span class="s1">&#39;nt&#39;</span><span class="p">:</span>

  819.         <span class="n">use_symlinks</span> <span class="o">=</span> <span class="kc">False</span>

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

  821.         <span class="n">use_symlinks</span> <span class="o">=</span> <span class="kc">True</span>

  822.     <span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s1">&#39;--symlinks&#39;</span><span class="p">,</span> <span class="n">default</span><span class="o">=</span><span class="n">use_symlinks</span><span class="p">,</span>

  823.                         <span class="n">action</span><span class="o">=</span><span class="s1">&#39;store_true&#39;</span><span class="p">,</span> <span class="n">dest</span><span class="o">=</span><span class="s1">&#39;symlinks&#39;</span><span class="p">,</span>

  824.                         <span class="n">help</span><span class="o">=</span><span class="s1">&#39;Try to use symlinks rather than copies, &#39;</span>

  825.                              <span class="s1">&#39;when symlinks are not the default for &#39;</span>

  826.                              <span class="s1">&#39;the platform.&#39;</span><span class="p">)</span>

  827.     <span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s1">&#39;--clear&#39;</span><span class="p">,</span> <span class="n">default</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span> <span class="n">action</span><span class="o">=</span><span class="s1">&#39;store_true&#39;</span><span class="p">,</span>

  828.                         <span class="n">dest</span><span class="o">=</span><span class="s1">&#39;clear&#39;</span><span class="p">,</span> <span class="n">help</span><span class="o">=</span><span class="s1">&#39;Delete the contents of the &#39;</span>

  829.                                            <span class="s1">&#39;virtual environment &#39;</span>

  830.                                            <span class="s1">&#39;directory if it already &#39;</span>

  831.                                            <span class="s1">&#39;exists, before virtual &#39;</span>

  832.                                            <span class="s1">&#39;environment creation.&#39;</span><span class="p">)</span>

  833.     <span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s1">&#39;--upgrade&#39;</span><span class="p">,</span> <span class="n">default</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span> <span class="n">action</span><span class="o">=</span><span class="s1">&#39;store_true&#39;</span><span class="p">,</span>

  834.                         <span class="n">dest</span><span class="o">=</span><span class="s1">&#39;upgrade&#39;</span><span class="p">,</span> <span class="n">help</span><span class="o">=</span><span class="s1">&#39;Upgrade the virtual &#39;</span>

  835.                                              <span class="s1">&#39;environment directory to &#39;</span>

  836.                                              <span class="s1">&#39;use this version of &#39;</span>

  837.                                              <span class="s1">&#39;Python, assuming Python &#39;</span>

  838.                                              <span class="s1">&#39;has been upgraded &#39;</span>

  839.                                              <span class="s1">&#39;in-place.&#39;</span><span class="p">)</span>

  840.     <span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s1">&#39;--verbose&#39;</span><span class="p">,</span> <span class="n">default</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span> <span class="n">action</span><span class="o">=</span><span class="s1">&#39;store_true&#39;</span><span class="p">,</span>

  841.                         <span class="n">dest</span><span class="o">=</span><span class="s1">&#39;verbose&#39;</span><span class="p">,</span> <span class="n">help</span><span class="o">=</span><span class="s1">&#39;Display the output &#39;</span>

  842.                                              <span class="s1">&#39;from the scripts which &#39;</span>

  843.                                              <span class="s1">&#39;install setuptools and pip.&#39;</span><span class="p">)</span>

  844.     <span class="n">options</span> <span class="o">=</span> <span class="n">parser</span><span class="o">.</span><span class="n">parse_args</span><span class="p">(</span><span class="n">args</span><span class="p">)</span>

  845.     <span class="k">if</span> <span class="n">options</span><span class="o">.</span><span class="n">upgrade</span> <span class="ow">and</span> <span class="n">options</span><span class="o">.</span><span class="n">clear</span><span class="p">:</span>

  846.         <span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s1">&#39;you cannot supply --upgrade and --clear together.&#39;</span><span class="p">)</span>

  847.     <span class="n">builder</span> <span class="o">=</span> <span class="n">ExtendedEnvBuilder</span><span class="p">(</span><span class="n">system_site_packages</span><span class="o">=</span><span class="n">options</span><span class="o">.</span><span class="n">system_site</span><span class="p">,</span>

  848.                                    <span class="n">clear</span><span class="o">=</span><span class="n">options</span><span class="o">.</span><span class="n">clear</span><span class="p">,</span>

  849.                                    <span class="n">symlinks</span><span class="o">=</span><span class="n">options</span><span class="o">.</span><span class="n">symlinks</span><span class="p">,</span>

  850.                                    <span class="n">upgrade</span><span class="o">=</span><span class="n">options</span><span class="o">.</span><span class="n">upgrade</span><span class="p">,</span>

  851.                                    <span class="n">nodist</span><span class="o">=</span><span class="n">options</span><span class="o">.</span><span class="n">nodist</span><span class="p">,</span>

  852.                                    <span class="n">nopip</span><span class="o">=</span><span class="n">options</span><span class="o">.</span><span class="n">nopip</span><span class="p">,</span>

  853.                                    <span class="n">verbose</span><span class="o">=</span><span class="n">options</span><span class="o">.</span><span class="n">verbose</span><span class="p">)</span>

  854.     <span class="k">for</span> <span class="n">d</span> <span class="ow">in</span> <span class="n">options</span><span class="o">.</span><span class="n">dirs</span><span class="p">:</span>

  855.         <span class="n">builder</span><span class="o">.</span><span class="n">create</span><span class="p">(</span><span class="n">d</span><span class="p">)</span>

  856. 

  857. <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>

  858.     <span class="n">rc</span> <span class="o">=</span> <span class="mi">1</span>

  859.     <span class="k">try</span><span class="p">:</span>

  860.         <span class="n">main</span><span class="p">()</span>

  861.         <span class="n">rc</span> <span class="o">=</span> <span class="mi">0</span>

  862.     <span class="k">except</span> <span class="ne">Exception</span> <span class="k">as</span> <span class="n">e</span><span class="p">:</span>

  863.         <span class="nb">print</span><span class="p">(</span><span class="s1">&#39;Error: </span><span class="si">%s</span><span class="s1">&#39;</span> <span class="o">%</span> <span class="n">e</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>

  864.     <span class="n">sys</span><span class="o">.</span><span class="n">exit</span><span class="p">(</span><span class="n">rc</span><span class="p">)</span>

  865. </pre></div>

  866. </div>

  867. <p>This script is also available for download <a class="reference external" href="https://gist.github.com/vsajip/4673395">online</a>.</p>

  868. </section>

  869. </section>

  870. 

  871. 

  872.             <div class="clearer"></div>

  873.           </div>

  874.         </div>

  875.       </div>

  876.       <div class="sphinxsidebar" role="navigation" aria-label="main navigation">

  877.         <div class="sphinxsidebarwrapper">

  878.   <div>

  879.     <h3><a href="../contents.html">Table of Contents</a></h3>

  880.     <ul>

  881. <li><a class="reference internal" href="#"><code class="xref py py-mod docutils literal notranslate"><span class="pre">venv</span></code> — Creation of virtual environments</a><ul>

  882. <li><a class="reference internal" href="#creating-virtual-environments">Creating virtual environments</a></li>

  883. <li><a class="reference internal" href="#how-venvs-work">How venvs work</a></li>

  884. <li><a class="reference internal" href="#api">API</a></li>

  885. <li><a class="reference internal" href="#an-example-of-extending-envbuilder">An example of extending <code class="docutils literal notranslate"><span class="pre">EnvBuilder</span></code></a></li>

  886. </ul>

  887. </li>

  888. </ul>

  889. 

  890.   </div>

  891.   <div>

  892.     <h4>Previous topic</h4>

  893.     <p class="topless"><a href="ensurepip.html"

  894.                           title="previous chapter"><code class="xref py py-mod docutils literal notranslate"><span class="pre">ensurepip</span></code> — Bootstrapping the <code class="docutils literal notranslate"><span class="pre">pip</span></code> installer</a></p>

  895.   </div>

  896.   <div>

  897.     <h4>Next topic</h4>

  898.     <p class="topless"><a href="zipapp.html"

  899.                           title="next chapter"><code class="xref py py-mod docutils literal notranslate"><span class="pre">zipapp</span></code> — Manage executable Python zip archives</a></p>

  900.   </div>

  901.   <div role="note" aria-label="source link">

  902.     <h3>This Page</h3>

  903.     <ul class="this-page-menu">

  904.       <li><a href="../bugs.html">Report a Bug</a></li>

  905.       <li>

  906.         <a href="https://github.com/python/cpython/blob/main/Doc/library/venv.rst"

  907.             rel="nofollow">Show Source

  908.         </a>

  909.       </li>

  910.     </ul>

  911.   </div>

  912.         </div>

  913. <div id="sidebarbutton" title="Collapse sidebar">

  914. <span>«</span>

  915. </div>

  916. 

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  920.     <div class="related" role="navigation" aria-label="related navigation">

  921.       <h3>Navigation</h3>

  922.       <ul>

  923.         <li class="right" style="margin-right: 10px">

  924.           <a href="../genindex.html" title="General Index"

  925.              >index</a></li>

  926.         <li class="right" >

  927.           <a href="../py-modindex.html" title="Python Module Index"

  928.              >modules</a> |</li>

  929.         <li class="right" >

  930.           <a href="zipapp.html" title="zipapp — Manage executable Python zip archives"

  931.              >next</a> |</li>

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