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  99. <li><a class="reference internal" href="#tracebackexception-objects"><code class="xref py py-class docutils literal notranslate"><span class="pre">TracebackException</span></code> Objects</a></li>

  100. <li><a class="reference internal" href="#stacksummary-objects"><code class="xref py py-class docutils literal notranslate"><span class="pre">StackSummary</span></code> Objects</a></li>

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

  196. <span id="traceback-print-or-retrieve-a-stack-traceback"></span><h1><a class="reference internal" href="#module-traceback" title="traceback: Print or retrieve a stack traceback."><code class="xref py py-mod docutils literal notranslate"><span class="pre">traceback</span></code></a> — Print or retrieve a stack traceback<a class="headerlink" href="#module-traceback" title="Link to this heading">¶</a></h1>

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

  198. <hr class="docutils" />

  199. <p>This module provides a standard interface to extract, format and print stack

  200. traces of Python programs.  It exactly mimics the behavior of the Python

  201. interpreter when it prints a stack trace.  This is useful when you want to print

  202. stack traces under program control, such as in a “wrapper” around the

  203. interpreter.</p>

  204. <p id="index-0">The module uses <a class="reference internal" href="../reference/datamodel.html#traceback-objects"><span class="std std-ref">traceback objects</span></a> — these are

  205. objects of type <a class="reference internal" href="types.html#types.TracebackType" title="types.TracebackType"><code class="xref py py-class docutils literal notranslate"><span class="pre">types.TracebackType</span></code></a>,

  206. which are assigned to the <a class="reference internal" href="exceptions.html#BaseException.__traceback__" title="BaseException.__traceback__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__traceback__</span></code></a> field of

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

  208. <div class="admonition seealso">

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

  210. <dl class="simple">

  211. <dt>Module <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></dt><dd><p>Used to dump Python tracebacks explicitly, on a fault, after a timeout, or on a user signal.</p>

  212. </dd>

  213. <dt>Module <a class="reference internal" href="pdb.html#module-pdb" title="pdb: The Python debugger for interactive interpreters."><code class="xref py py-mod docutils literal notranslate"><span class="pre">pdb</span></code></a></dt><dd><p>Interactive source code debugger for Python programs.</p>

  214. </dd>

  215. </dl>

  216. </div>

  217. <p>The module defines the following functions:</p>

  218. <dl class="py function">

  219. <dt class="sig sig-object py" id="traceback.print_tb">

  220. <span class="sig-prename descclassname"><span class="pre">traceback.</span></span><span class="sig-name descname"><span class="pre">print_tb</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">tb</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">limit</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">file</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="#traceback.print_tb" title="Link to this definition">¶</a></dt>

  221. <dd><p>Print up to <em>limit</em> stack trace entries from

  222. <a class="reference internal" href="../reference/datamodel.html#traceback-objects"><span class="std std-ref">traceback object</span></a> <em>tb</em> (starting

  223. from the caller’s frame) if <em>limit</em> is positive.  Otherwise, print the last

  224. <code class="docutils literal notranslate"><span class="pre">abs(limit)</span></code> entries.  If <em>limit</em> is omitted or <code class="docutils literal notranslate"><span class="pre">None</span></code>, all entries are

  225. printed.  If <em>file</em> is omitted or <code class="docutils literal notranslate"><span class="pre">None</span></code>, the output goes to

  226. <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>; otherwise it should be an open

  227. <a class="reference internal" href="../glossary.html#term-file-object"><span class="xref std std-term">file</span></a> or <a class="reference internal" href="../glossary.html#term-file-like-object"><span class="xref std std-term">file-like object</span></a> to

  228. receive the output.</p>

  229. <div class="versionchanged">

  230. <p><span class="versionmodified changed">Changed in version 3.5: </span>Added negative <em>limit</em> support.</p>

  231. </div>

  232. </dd></dl>

  233. 

  234. <dl class="py function">

  235. <dt class="sig sig-object py" id="traceback.print_exception">

  236. <span class="sig-prename descclassname"><span class="pre">traceback.</span></span><span class="sig-name descname"><span class="pre">print_exception</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">exc</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">/</span></span></em>, <span class="optional">[</span><em class="sig-param"><span class="n"><span class="pre">value</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">tb</span></span></em>, <span class="optional">]</span><em class="sig-param"><span class="n"><span class="pre">limit=None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">file=None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">chain=True</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#traceback.print_exception" title="Link to this definition">¶</a></dt>

  237. <dd><p>Print exception information and stack trace entries from

  238. <a class="reference internal" href="../reference/datamodel.html#traceback-objects"><span class="std std-ref">traceback object</span></a>

  239. <em>tb</em> to <em>file</em>. This differs from <a class="reference internal" href="#traceback.print_tb" title="traceback.print_tb"><code class="xref py py-func docutils literal notranslate"><span class="pre">print_tb()</span></code></a> in the following

  240. ways:</p>

  241. <ul class="simple">

  242. <li><p>if <em>tb</em> is not <code class="docutils literal notranslate"><span class="pre">None</span></code>, it prints a header <code class="docutils literal notranslate"><span class="pre">Traceback</span> <span class="pre">(most</span> <span class="pre">recent</span>

  243. <span class="pre">call</span> <span class="pre">last):</span></code></p></li>

  244. <li><p>it prints the exception type and <em>value</em> after the stack trace</p></li>

  245. </ul>

  246. <ul class="simple" id="index-1">

  247. <li><p>if <em>type(value)</em> is <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> and <em>value</em> has the appropriate

  248. format, it prints the line where the syntax error occurred with a caret

  249. indicating the approximate position of the error.</p></li>

  250. </ul>

  251. <p>Since Python 3.10, instead of passing <em>value</em> and <em>tb</em>, an exception object

  252. can be passed as the first argument. If <em>value</em> and <em>tb</em> are provided, the

  253. first argument is ignored in order to provide backwards compatibility.</p>

  254. <p>The optional <em>limit</em> argument has the same meaning as for <a class="reference internal" href="#traceback.print_tb" title="traceback.print_tb"><code class="xref py py-func docutils literal notranslate"><span class="pre">print_tb()</span></code></a>.

  255. If <em>chain</em> is true (the default), then chained exceptions (the

  256. <a class="reference internal" href="exceptions.html#BaseException.__cause__" title="BaseException.__cause__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__cause__</span></code></a> or <a class="reference internal" href="exceptions.html#BaseException.__context__" title="BaseException.__context__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__context__</span></code></a>

  257. attributes of the exception) will be

  258. printed as well, like the interpreter itself does when printing an unhandled

  259. exception.</p>

  260. <div class="versionchanged">

  261. <p><span class="versionmodified changed">Changed in version 3.5: </span>The <em>etype</em> argument is ignored and inferred from the type of <em>value</em>.</p>

  262. </div>

  263. <div class="versionchanged">

  264. <p><span class="versionmodified changed">Changed in version 3.10: </span>The <em>etype</em> parameter has been renamed to <em>exc</em> and is now

  265. positional-only.</p>

  266. </div>

  267. </dd></dl>

  268. 

  269. <dl class="py function">

  270. <dt class="sig sig-object py" id="traceback.print_exc">

  271. <span class="sig-prename descclassname"><span class="pre">traceback.</span></span><span class="sig-name descname"><span class="pre">print_exc</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">limit</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">file</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">chain</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="#traceback.print_exc" title="Link to this definition">¶</a></dt>

  272. <dd><p>This is a shorthand for <code class="docutils literal notranslate"><span class="pre">print_exception(sys.exception(),</span> <span class="pre">limit,</span> <span class="pre">file,</span>

  273. <span class="pre">chain)</span></code>.</p>

  274. </dd></dl>

  275. 

  276. <dl class="py function">

  277. <dt class="sig sig-object py" id="traceback.print_last">

  278. <span class="sig-prename descclassname"><span class="pre">traceback.</span></span><span class="sig-name descname"><span class="pre">print_last</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">limit</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">file</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">chain</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="#traceback.print_last" title="Link to this definition">¶</a></dt>

  279. <dd><p>This is a shorthand for <code class="docutils literal notranslate"><span class="pre">print_exception(sys.last_exc,</span> <span class="pre">limit,</span> <span class="pre">file,</span>

  280. <span class="pre">chain)</span></code>.  In general it will work only after an exception has reached

  281. an interactive prompt (see <a class="reference internal" href="sys.html#sys.last_exc" title="sys.last_exc"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.last_exc</span></code></a>).</p>

  282. </dd></dl>

  283. 

  284. <dl class="py function">

  285. <dt class="sig sig-object py" id="traceback.print_stack">

  286. <span class="sig-prename descclassname"><span class="pre">traceback.</span></span><span class="sig-name descname"><span class="pre">print_stack</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">f</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">limit</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">file</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="#traceback.print_stack" title="Link to this definition">¶</a></dt>

  287. <dd><p>Print up to <em>limit</em> stack trace entries (starting from the invocation

  288. point) if <em>limit</em> is positive.  Otherwise, print the last <code class="docutils literal notranslate"><span class="pre">abs(limit)</span></code>

  289. entries.  If <em>limit</em> is omitted or <code class="docutils literal notranslate"><span class="pre">None</span></code>, all entries are printed.

  290. The optional <em>f</em> argument can be used to specify an alternate

  291. <a class="reference internal" href="../reference/datamodel.html#frame-objects"><span class="std std-ref">stack frame</span></a>

  292. to start.  The optional <em>file</em> argument has the same meaning as for

  293. <a class="reference internal" href="#traceback.print_tb" title="traceback.print_tb"><code class="xref py py-func docutils literal notranslate"><span class="pre">print_tb()</span></code></a>.</p>

  294. <div class="versionchanged">

  295. <p><span class="versionmodified changed">Changed in version 3.5: </span>Added negative <em>limit</em> support.</p>

  296. </div>

  297. </dd></dl>

  298. 

  299. <dl class="py function">

  300. <dt class="sig sig-object py" id="traceback.extract_tb">

  301. <span class="sig-prename descclassname"><span class="pre">traceback.</span></span><span class="sig-name descname"><span class="pre">extract_tb</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">tb</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">limit</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="#traceback.extract_tb" title="Link to this definition">¶</a></dt>

  302. <dd><p>Return a <a class="reference internal" href="#traceback.StackSummary" title="traceback.StackSummary"><code class="xref py py-class docutils literal notranslate"><span class="pre">StackSummary</span></code></a> object representing a list of “pre-processed”

  303. stack trace entries extracted from the

  304. <a class="reference internal" href="../reference/datamodel.html#traceback-objects"><span class="std std-ref">traceback object</span></a> <em>tb</em>.  It is useful

  305. for alternate formatting of stack traces.  The optional <em>limit</em> argument has

  306. the same meaning as for <a class="reference internal" href="#traceback.print_tb" title="traceback.print_tb"><code class="xref py py-func docutils literal notranslate"><span class="pre">print_tb()</span></code></a>.  A “pre-processed” stack trace

  307. entry is a <a class="reference internal" href="#traceback.FrameSummary" title="traceback.FrameSummary"><code class="xref py py-class docutils literal notranslate"><span class="pre">FrameSummary</span></code></a> object containing attributes

  308. <a class="reference internal" href="#traceback.FrameSummary.filename" title="traceback.FrameSummary.filename"><code class="xref py py-attr docutils literal notranslate"><span class="pre">filename</span></code></a>, <a class="reference internal" href="#traceback.FrameSummary.lineno" title="traceback.FrameSummary.lineno"><code class="xref py py-attr docutils literal notranslate"><span class="pre">lineno</span></code></a>,

  309. <a class="reference internal" href="#traceback.FrameSummary.name" title="traceback.FrameSummary.name"><code class="xref py py-attr docutils literal notranslate"><span class="pre">name</span></code></a>, and <a class="reference internal" href="#traceback.FrameSummary.line" title="traceback.FrameSummary.line"><code class="xref py py-attr docutils literal notranslate"><span class="pre">line</span></code></a> representing the

  310. information that is usually printed for a stack trace.</p>

  311. </dd></dl>

  312. 

  313. <dl class="py function">

  314. <dt class="sig sig-object py" id="traceback.extract_stack">

  315. <span class="sig-prename descclassname"><span class="pre">traceback.</span></span><span class="sig-name descname"><span class="pre">extract_stack</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">f</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">limit</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="#traceback.extract_stack" title="Link to this definition">¶</a></dt>

  316. <dd><p>Extract the raw traceback from the current

  317. <a class="reference internal" href="../reference/datamodel.html#frame-objects"><span class="std std-ref">stack frame</span></a>.  The return value has

  318. the same format as for <a class="reference internal" href="#traceback.extract_tb" title="traceback.extract_tb"><code class="xref py py-func docutils literal notranslate"><span class="pre">extract_tb()</span></code></a>.  The optional <em>f</em> and <em>limit</em>

  319. arguments have the same meaning as for <a class="reference internal" href="#traceback.print_stack" title="traceback.print_stack"><code class="xref py py-func docutils literal notranslate"><span class="pre">print_stack()</span></code></a>.</p>

  320. </dd></dl>

  321. 

  322. <dl class="py function">

  323. <dt class="sig sig-object py" id="traceback.format_list">

  324. <span class="sig-prename descclassname"><span class="pre">traceback.</span></span><span class="sig-name descname"><span class="pre">format_list</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">extracted_list</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#traceback.format_list" title="Link to this definition">¶</a></dt>

  325. <dd><p>Given a list of tuples or <a class="reference internal" href="#traceback.FrameSummary" title="traceback.FrameSummary"><code class="xref py py-class docutils literal notranslate"><span class="pre">FrameSummary</span></code></a> objects as returned by

  326. <a class="reference internal" href="#traceback.extract_tb" title="traceback.extract_tb"><code class="xref py py-func docutils literal notranslate"><span class="pre">extract_tb()</span></code></a> or <a class="reference internal" href="#traceback.extract_stack" title="traceback.extract_stack"><code class="xref py py-func docutils literal notranslate"><span class="pre">extract_stack()</span></code></a>, return a list of strings ready

  327. for printing.  Each string in the resulting list corresponds to the item with

  328. the same index in the argument list.  Each string ends in a newline; the

  329. strings may contain internal newlines as well, for those items whose source

  330. text line is not <code class="docutils literal notranslate"><span class="pre">None</span></code>.</p>

  331. </dd></dl>

  332. 

  333. <dl class="py function">

  334. <dt class="sig sig-object py" id="traceback.format_exception_only">

  335. <span class="sig-prename descclassname"><span class="pre">traceback.</span></span><span class="sig-name descname"><span class="pre">format_exception_only</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">exc</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">/</span></span></em><span class="optional">[</span>, <em class="sig-param"><span class="n"><span class="pre">value</span></span></em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#traceback.format_exception_only" title="Link to this definition">¶</a></dt>

  336. <dd><p>Format the exception part of a traceback using an exception value such as

  337. given by <a class="reference internal" href="sys.html#sys.last_value" title="sys.last_value"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.last_value</span></code></a>.  The return value is a list of strings, each

  338. ending in a newline.  The list contains the exception’s message, which is

  339. normally a single string; however, for <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> exceptions, it

  340. contains several lines that (when printed) display detailed information

  341. about where the syntax error occurred. Following the message, the list

  342. contains the exception’s <a class="reference internal" href="exceptions.html#BaseException.__notes__" title="BaseException.__notes__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">notes</span></code></a>.</p>

  343. <p>Since Python 3.10, instead of passing <em>value</em>, an exception object

  344. can be passed as the first argument.  If <em>value</em> is provided, the first

  345. argument is ignored in order to provide backwards compatibility.</p>

  346. <div class="versionchanged">

  347. <p><span class="versionmodified changed">Changed in version 3.10: </span>The <em>etype</em> parameter has been renamed to <em>exc</em> and is now

  348. positional-only.</p>

  349. </div>

  350. <div class="versionchanged">

  351. <p><span class="versionmodified changed">Changed in version 3.11: </span>The returned list now includes any

  352. <a class="reference internal" href="exceptions.html#BaseException.__notes__" title="BaseException.__notes__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">notes</span></code></a> attached to the exception.</p>

  353. </div>

  354. </dd></dl>

  355. 

  356. <dl class="py function">

  357. <dt class="sig sig-object py" id="traceback.format_exception">

  358. <span class="sig-prename descclassname"><span class="pre">traceback.</span></span><span class="sig-name descname"><span class="pre">format_exception</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">exc</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">/</span></span></em>, <span class="optional">[</span><em class="sig-param"><span class="n"><span class="pre">value</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">tb</span></span></em>, <span class="optional">]</span><em class="sig-param"><span class="n"><span class="pre">limit=None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">chain=True</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#traceback.format_exception" title="Link to this definition">¶</a></dt>

  359. <dd><p>Format a stack trace and the exception information.  The arguments  have the

  360. same meaning as the corresponding arguments to <a class="reference internal" href="#traceback.print_exception" title="traceback.print_exception"><code class="xref py py-func docutils literal notranslate"><span class="pre">print_exception()</span></code></a>.  The

  361. return value is a list of strings, each ending in a newline and some

  362. containing internal newlines.  When these lines are concatenated and printed,

  363. exactly the same text is printed as does <a class="reference internal" href="#traceback.print_exception" title="traceback.print_exception"><code class="xref py py-func docutils literal notranslate"><span class="pre">print_exception()</span></code></a>.</p>

  364. <div class="versionchanged">

  365. <p><span class="versionmodified changed">Changed in version 3.5: </span>The <em>etype</em> argument is ignored and inferred from the type of <em>value</em>.</p>

  366. </div>

  367. <div class="versionchanged">

  368. <p><span class="versionmodified changed">Changed in version 3.10: </span>This function’s behavior and signature were modified to match

  369. <a class="reference internal" href="#traceback.print_exception" title="traceback.print_exception"><code class="xref py py-func docutils literal notranslate"><span class="pre">print_exception()</span></code></a>.</p>

  370. </div>

  371. </dd></dl>

  372. 

  373. <dl class="py function">

  374. <dt class="sig sig-object py" id="traceback.format_exc">

  375. <span class="sig-prename descclassname"><span class="pre">traceback.</span></span><span class="sig-name descname"><span class="pre">format_exc</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">limit</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">chain</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="#traceback.format_exc" title="Link to this definition">¶</a></dt>

  376. <dd><p>This is like <code class="docutils literal notranslate"><span class="pre">print_exc(limit)</span></code> but returns a string instead of printing to

  377. a file.</p>

  378. </dd></dl>

  379. 

  380. <dl class="py function">

  381. <dt class="sig sig-object py" id="traceback.format_tb">

  382. <span class="sig-prename descclassname"><span class="pre">traceback.</span></span><span class="sig-name descname"><span class="pre">format_tb</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">tb</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">limit</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="#traceback.format_tb" title="Link to this definition">¶</a></dt>

  383. <dd><p>A shorthand for <code class="docutils literal notranslate"><span class="pre">format_list(extract_tb(tb,</span> <span class="pre">limit))</span></code>.</p>

  384. </dd></dl>

  385. 

  386. <dl class="py function">

  387. <dt class="sig sig-object py" id="traceback.format_stack">

  388. <span class="sig-prename descclassname"><span class="pre">traceback.</span></span><span class="sig-name descname"><span class="pre">format_stack</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">f</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">limit</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="#traceback.format_stack" title="Link to this definition">¶</a></dt>

  389. <dd><p>A shorthand for <code class="docutils literal notranslate"><span class="pre">format_list(extract_stack(f,</span> <span class="pre">limit))</span></code>.</p>

  390. </dd></dl>

  391. 

  392. <dl class="py function">

  393. <dt class="sig sig-object py" id="traceback.clear_frames">

  394. <span class="sig-prename descclassname"><span class="pre">traceback.</span></span><span class="sig-name descname"><span class="pre">clear_frames</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">tb</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#traceback.clear_frames" title="Link to this definition">¶</a></dt>

  395. <dd><p>Clears the local variables of all the stack frames in a

  396. <a class="reference internal" href="../reference/datamodel.html#traceback-objects"><span class="std std-ref">traceback</span></a> <em>tb</em>

  397. by calling the <a class="reference internal" href="../reference/datamodel.html#frame.clear" title="frame.clear"><code class="xref py py-meth docutils literal notranslate"><span class="pre">clear()</span></code></a> method of each

  398. <a class="reference internal" href="../reference/datamodel.html#frame-objects"><span class="std std-ref">frame object</span></a>.</p>

  399. <div class="versionadded">

  400. <p><span class="versionmodified added">New in version 3.4.</span></p>

  401. </div>

  402. </dd></dl>

  403. 

  404. <dl class="py function">

  405. <dt class="sig sig-object py" id="traceback.walk_stack">

  406. <span class="sig-prename descclassname"><span class="pre">traceback.</span></span><span class="sig-name descname"><span class="pre">walk_stack</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="#traceback.walk_stack" title="Link to this definition">¶</a></dt>

  407. <dd><p>Walk a stack following <a class="reference internal" href="../reference/datamodel.html#frame.f_back" title="frame.f_back"><code class="xref py py-attr docutils literal notranslate"><span class="pre">f.f_back</span></code></a> from the given frame,

  408. yielding the frame

  409. and line number for each frame. If <em>f</em> is <code class="docutils literal notranslate"><span class="pre">None</span></code>, the current stack is

  410. used. This helper is used with <a class="reference internal" href="#traceback.StackSummary.extract" title="traceback.StackSummary.extract"><code class="xref py py-meth docutils literal notranslate"><span class="pre">StackSummary.extract()</span></code></a>.</p>

  411. <div class="versionadded">

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

  413. </div>

  414. </dd></dl>

  415. 

  416. <dl class="py function">

  417. <dt class="sig sig-object py" id="traceback.walk_tb">

  418. <span class="sig-prename descclassname"><span class="pre">traceback.</span></span><span class="sig-name descname"><span class="pre">walk_tb</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">tb</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#traceback.walk_tb" title="Link to this definition">¶</a></dt>

  419. <dd><p>Walk a traceback following <a class="reference internal" href="../reference/datamodel.html#traceback.tb_next" title="traceback.tb_next"><code class="xref py py-attr docutils literal notranslate"><span class="pre">tb_next</span></code></a> yielding the frame and

  420. line number

  421. for each frame. This helper is used with <a class="reference internal" href="#traceback.StackSummary.extract" title="traceback.StackSummary.extract"><code class="xref py py-meth docutils literal notranslate"><span class="pre">StackSummary.extract()</span></code></a>.</p>

  422. <div class="versionadded">

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

  424. </div>

  425. </dd></dl>

  426. 

  427. <p>The module also defines the following classes:</p>

  428. <section id="tracebackexception-objects">

  429. <h2><code class="xref py py-class docutils literal notranslate"><span class="pre">TracebackException</span></code> Objects<a class="headerlink" href="#tracebackexception-objects" title="Link to this heading">¶</a></h2>

  430. <div class="versionadded">

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

  432. </div>

  433. <p><code class="xref py py-class docutils literal notranslate"><span class="pre">TracebackException</span></code> objects are created from actual exceptions to

  434. capture data for later printing in a lightweight fashion.</p>

  435. <dl class="py class">

  436. <dt class="sig sig-object py" id="traceback.TracebackException">

  437. <em class="property"><span class="pre">class</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">traceback.</span></span><span class="sig-name descname"><span class="pre">TracebackException</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">exc_type</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">exc_value</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">exc_traceback</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">limit</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">lookup_lines</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">True</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">capture_locals</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">compact</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">max_group_width</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">15</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">max_group_depth</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">10</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#traceback.TracebackException" title="Link to this definition">¶</a></dt>

  438. <dd><p>Capture an exception for later rendering. <em>limit</em>, <em>lookup_lines</em> and

  439. <em>capture_locals</em> are as for the <a class="reference internal" href="#traceback.StackSummary" title="traceback.StackSummary"><code class="xref py py-class docutils literal notranslate"><span class="pre">StackSummary</span></code></a> class.</p>

  440. <p>If <em>compact</em> is true, only data that is required by

  441. <code class="xref py py-class docutils literal notranslate"><span class="pre">TracebackException</span></code>’s <a class="reference internal" href="functions.html#format" title="format"><code class="xref py py-meth docutils literal notranslate"><span class="pre">format()</span></code></a> method

  442. is saved in the class attributes. In particular, the

  443. <a class="reference internal" href="#traceback.TracebackException.__context__" title="traceback.TracebackException.__context__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__context__</span></code></a> field is calculated only if <a class="reference internal" href="#traceback.TracebackException.__cause__" title="traceback.TracebackException.__cause__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__cause__</span></code></a> is

  444. <code class="docutils literal notranslate"><span class="pre">None</span></code> and <a class="reference internal" href="#traceback.TracebackException.__suppress_context__" title="traceback.TracebackException.__suppress_context__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__suppress_context__</span></code></a> is false.</p>

  445. <p>Note that when locals are captured, they are also shown in the traceback.</p>

  446. <p><em>max_group_width</em> and <em>max_group_depth</em> control the formatting of exception

  447. groups (see <a class="reference internal" href="exceptions.html#BaseExceptionGroup" title="BaseExceptionGroup"><code class="xref py py-exc docutils literal notranslate"><span class="pre">BaseExceptionGroup</span></code></a>). The depth refers to the nesting

  448. level of the group, and the width refers to the size of a single exception

  449. group’s exceptions array. The formatted output is truncated when either

  450. limit is exceeded.</p>

  451. <div class="versionchanged">

  452. <p><span class="versionmodified changed">Changed in version 3.10: </span>Added the <em>compact</em> parameter.</p>

  453. </div>

  454. <div class="versionchanged">

  455. <p><span class="versionmodified changed">Changed in version 3.11: </span>Added the <em>max_group_width</em> and <em>max_group_depth</em> parameters.</p>

  456. </div>

  457. <dl class="py attribute">

  458. <dt class="sig sig-object py" id="traceback.TracebackException.__cause__">

  459. <span class="sig-name descname"><span class="pre">__cause__</span></span><a class="headerlink" href="#traceback.TracebackException.__cause__" title="Link to this definition">¶</a></dt>

  460. <dd><p>A <code class="xref py py-class docutils literal notranslate"><span class="pre">TracebackException</span></code> of the original

  461. <a class="reference internal" href="exceptions.html#BaseException.__cause__" title="BaseException.__cause__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__cause__</span></code></a>.</p>

  462. </dd></dl>

  463. 

  464. <dl class="py attribute">

  465. <dt class="sig sig-object py" id="traceback.TracebackException.__context__">

  466. <span class="sig-name descname"><span class="pre">__context__</span></span><a class="headerlink" href="#traceback.TracebackException.__context__" title="Link to this definition">¶</a></dt>

  467. <dd><p>A <code class="xref py py-class docutils literal notranslate"><span class="pre">TracebackException</span></code> of the original

  468. <a class="reference internal" href="exceptions.html#BaseException.__context__" title="BaseException.__context__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__context__</span></code></a>.</p>

  469. </dd></dl>

  470. 

  471. <dl class="py attribute">

  472. <dt class="sig sig-object py" id="traceback.TracebackException.exceptions">

  473. <span class="sig-name descname"><span class="pre">exceptions</span></span><a class="headerlink" href="#traceback.TracebackException.exceptions" title="Link to this definition">¶</a></dt>

  474. <dd><p>If <code class="docutils literal notranslate"><span class="pre">self</span></code> represents an <a class="reference internal" href="exceptions.html#ExceptionGroup" title="ExceptionGroup"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ExceptionGroup</span></code></a>, this field holds a list of

  475. <code class="xref py py-class docutils literal notranslate"><span class="pre">TracebackException</span></code> instances representing the nested exceptions.

  476. Otherwise it is <code class="docutils literal notranslate"><span class="pre">None</span></code>.</p>

  477. <div class="versionadded">

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

  479. </div>

  480. </dd></dl>

  481. 

  482. <dl class="py attribute">

  483. <dt class="sig sig-object py" id="traceback.TracebackException.__suppress_context__">

  484. <span class="sig-name descname"><span class="pre">__suppress_context__</span></span><a class="headerlink" href="#traceback.TracebackException.__suppress_context__" title="Link to this definition">¶</a></dt>

  485. <dd><p>The <a class="reference internal" href="exceptions.html#BaseException.__suppress_context__" title="BaseException.__suppress_context__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__suppress_context__</span></code></a> value from the original

  486. exception.</p>

  487. </dd></dl>

  488. 

  489. <dl class="py attribute">

  490. <dt class="sig sig-object py" id="traceback.TracebackException.__notes__">

  491. <span class="sig-name descname"><span class="pre">__notes__</span></span><a class="headerlink" href="#traceback.TracebackException.__notes__" title="Link to this definition">¶</a></dt>

  492. <dd><p>The <a class="reference internal" href="exceptions.html#BaseException.__notes__" title="BaseException.__notes__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__notes__</span></code></a> value from the original exception,

  493. or <code class="docutils literal notranslate"><span class="pre">None</span></code>

  494. if the exception does not have any notes. If it is not <code class="docutils literal notranslate"><span class="pre">None</span></code>

  495. is it formatted in the traceback after the exception string.</p>

  496. <div class="versionadded">

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

  498. </div>

  499. </dd></dl>

  500. 

  501. <dl class="py attribute">

  502. <dt class="sig sig-object py" id="traceback.TracebackException.stack">

  503. <span class="sig-name descname"><span class="pre">stack</span></span><a class="headerlink" href="#traceback.TracebackException.stack" title="Link to this definition">¶</a></dt>

  504. <dd><p>A <a class="reference internal" href="#traceback.StackSummary" title="traceback.StackSummary"><code class="xref py py-class docutils literal notranslate"><span class="pre">StackSummary</span></code></a> representing the traceback.</p>

  505. </dd></dl>

  506. 

  507. <dl class="py attribute">

  508. <dt class="sig sig-object py" id="traceback.TracebackException.exc_type">

  509. <span class="sig-name descname"><span class="pre">exc_type</span></span><a class="headerlink" href="#traceback.TracebackException.exc_type" title="Link to this definition">¶</a></dt>

  510. <dd><p>The class of the original traceback.</p>

  511. </dd></dl>

  512. 

  513. <dl class="py attribute">

  514. <dt class="sig sig-object py" id="traceback.TracebackException.filename">

  515. <span class="sig-name descname"><span class="pre">filename</span></span><a class="headerlink" href="#traceback.TracebackException.filename" title="Link to this definition">¶</a></dt>

  516. <dd><p>For syntax errors - the file name where the error occurred.</p>

  517. </dd></dl>

  518. 

  519. <dl class="py attribute">

  520. <dt class="sig sig-object py" id="traceback.TracebackException.lineno">

  521. <span class="sig-name descname"><span class="pre">lineno</span></span><a class="headerlink" href="#traceback.TracebackException.lineno" title="Link to this definition">¶</a></dt>

  522. <dd><p>For syntax errors - the line number where the error occurred.</p>

  523. </dd></dl>

  524. 

  525. <dl class="py attribute">

  526. <dt class="sig sig-object py" id="traceback.TracebackException.end_lineno">

  527. <span class="sig-name descname"><span class="pre">end_lineno</span></span><a class="headerlink" href="#traceback.TracebackException.end_lineno" title="Link to this definition">¶</a></dt>

  528. <dd><p>For syntax errors - the end line number where the error occurred.

  529. Can be <code class="docutils literal notranslate"><span class="pre">None</span></code> if not present.</p>

  530. <div class="versionadded">

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

  532. </div>

  533. </dd></dl>

  534. 

  535. <dl class="py attribute">

  536. <dt class="sig sig-object py" id="traceback.TracebackException.text">

  537. <span class="sig-name descname"><span class="pre">text</span></span><a class="headerlink" href="#traceback.TracebackException.text" title="Link to this definition">¶</a></dt>

  538. <dd><p>For syntax errors - the text where the error occurred.</p>

  539. </dd></dl>

  540. 

  541. <dl class="py attribute">

  542. <dt class="sig sig-object py" id="traceback.TracebackException.offset">

  543. <span class="sig-name descname"><span class="pre">offset</span></span><a class="headerlink" href="#traceback.TracebackException.offset" title="Link to this definition">¶</a></dt>

  544. <dd><p>For syntax errors - the offset into the text where the error occurred.</p>

  545. </dd></dl>

  546. 

  547. <dl class="py attribute">

  548. <dt class="sig sig-object py" id="traceback.TracebackException.end_offset">

  549. <span class="sig-name descname"><span class="pre">end_offset</span></span><a class="headerlink" href="#traceback.TracebackException.end_offset" title="Link to this definition">¶</a></dt>

  550. <dd><p>For syntax errors - the end offset into the text where the error occurred.

  551. Can be <code class="docutils literal notranslate"><span class="pre">None</span></code> if not present.</p>

  552. <div class="versionadded">

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

  554. </div>

  555. </dd></dl>

  556. 

  557. <dl class="py attribute">

  558. <dt class="sig sig-object py" id="traceback.TracebackException.msg">

  559. <span class="sig-name descname"><span class="pre">msg</span></span><a class="headerlink" href="#traceback.TracebackException.msg" title="Link to this definition">¶</a></dt>

  560. <dd><p>For syntax errors - the compiler error message.</p>

  561. </dd></dl>

  562. 

  563. <dl class="py method">

  564. <dt class="sig sig-object py" id="traceback.TracebackException.from_exception">

  565. <em class="property"><span class="pre">classmethod</span><span class="w"> </span></em><span class="sig-name descname"><span class="pre">from_exception</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">exc</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">limit</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">lookup_lines</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">True</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">capture_locals</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="#traceback.TracebackException.from_exception" title="Link to this definition">¶</a></dt>

  566. <dd><p>Capture an exception for later rendering. <em>limit</em>, <em>lookup_lines</em> and

  567. <em>capture_locals</em> are as for the <a class="reference internal" href="#traceback.StackSummary" title="traceback.StackSummary"><code class="xref py py-class docutils literal notranslate"><span class="pre">StackSummary</span></code></a> class.</p>

  568. <p>Note that when locals are captured, they are also shown in the traceback.</p>

  569. </dd></dl>

  570. 

  571. <dl class="py method">

  572. <dt class="sig sig-object py" id="traceback.TracebackException.print">

  573. <span class="sig-name descname"><span class="pre">print</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">file</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">chain</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="#traceback.TracebackException.print" title="Link to this definition">¶</a></dt>

  574. <dd><p>Print to <em>file</em> (default <code class="docutils literal notranslate"><span class="pre">sys.stderr</span></code>) the exception information returned by

  575. <a class="reference internal" href="functions.html#format" title="format"><code class="xref py py-meth docutils literal notranslate"><span class="pre">format()</span></code></a>.</p>

  576. <div class="versionadded">

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

  578. </div>

  579. </dd></dl>

  580. 

  581. <dl class="py method">

  582. <dt class="sig sig-object py" id="traceback.TracebackException.format">

  583. <span class="sig-name descname"><span class="pre">format</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">chain</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="#traceback.TracebackException.format" title="Link to this definition">¶</a></dt>

  584. <dd><p>Format the exception.</p>

  585. <p>If <em>chain</em> is not <code class="docutils literal notranslate"><span class="pre">True</span></code>, <a class="reference internal" href="#traceback.TracebackException.__cause__" title="traceback.TracebackException.__cause__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__cause__</span></code></a> and <a class="reference internal" href="#traceback.TracebackException.__context__" title="traceback.TracebackException.__context__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__context__</span></code></a>

  586. will not be formatted.</p>

  587. <p>The return value is a generator of strings, each ending in a newline and

  588. some containing internal newlines. <a class="reference internal" href="#traceback.print_exception" title="traceback.print_exception"><code class="xref py py-func docutils literal notranslate"><span class="pre">print_exception()</span></code></a>

  589. is a wrapper around this method which just prints the lines to a file.</p>

  590. </dd></dl>

  591. 

  592. <dl class="py method">

  593. <dt class="sig sig-object py" id="traceback.TracebackException.format_exception_only">

  594. <span class="sig-name descname"><span class="pre">format_exception_only</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#traceback.TracebackException.format_exception_only" title="Link to this definition">¶</a></dt>

  595. <dd><p>Format the exception part of the traceback.</p>

  596. <p>The return value is a generator of strings, each ending in a newline.</p>

  597. <p>The generator emits the exception’s message followed by its notes

  598. (if it has any). The exception message is normally a single string;

  599. however, for <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> exceptions, it consists of several

  600. lines that (when printed) display detailed information about where

  601. the syntax error occurred.</p>

  602. <div class="versionchanged">

  603. <p><span class="versionmodified changed">Changed in version 3.11: </span>The exception’s <a class="reference internal" href="exceptions.html#BaseException.__notes__" title="BaseException.__notes__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">notes</span></code></a> are now

  604. included in the output.</p>

  605. </div>

  606. </dd></dl>

  607. 

  608. </dd></dl>

  609. 

  610. </section>

  611. <section id="stacksummary-objects">

  612. <h2><code class="xref py py-class docutils literal notranslate"><span class="pre">StackSummary</span></code> Objects<a class="headerlink" href="#stacksummary-objects" title="Link to this heading">¶</a></h2>

  613. <div class="versionadded">

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

  615. </div>

  616. <p><code class="xref py py-class docutils literal notranslate"><span class="pre">StackSummary</span></code> objects represent a call stack ready for formatting.</p>

  617. <dl class="py class">

  618. <dt class="sig sig-object py" id="traceback.StackSummary">

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

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

  621. <dt class="sig sig-object py" id="traceback.StackSummary.extract">

  622. <em class="property"><span class="pre">classmethod</span><span class="w"> </span></em><span class="sig-name descname"><span class="pre">extract</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">frame_gen</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">limit</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">lookup_lines</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">True</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">capture_locals</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="#traceback.StackSummary.extract" title="Link to this definition">¶</a></dt>

  623. <dd><p>Construct a <code class="xref py py-class docutils literal notranslate"><span class="pre">StackSummary</span></code> object from a frame generator (such as

  624. is returned by <a class="reference internal" href="#traceback.walk_stack" title="traceback.walk_stack"><code class="xref py py-func docutils literal notranslate"><span class="pre">walk_stack()</span></code></a> or

  625. <a class="reference internal" href="#traceback.walk_tb" title="traceback.walk_tb"><code class="xref py py-func docutils literal notranslate"><span class="pre">walk_tb()</span></code></a>).</p>

  626. <p>If <em>limit</em> is supplied, only this many frames are taken from <em>frame_gen</em>.

  627. If <em>lookup_lines</em> is <code class="docutils literal notranslate"><span class="pre">False</span></code>, the returned <a class="reference internal" href="#traceback.FrameSummary" title="traceback.FrameSummary"><code class="xref py py-class docutils literal notranslate"><span class="pre">FrameSummary</span></code></a>

  628. objects will not have read their lines in yet, making the cost of

  629. creating the <code class="xref py py-class docutils literal notranslate"><span class="pre">StackSummary</span></code> cheaper (which may be valuable if it

  630. may not actually get formatted). If <em>capture_locals</em> is <code class="docutils literal notranslate"><span class="pre">True</span></code> the

  631. local variables in each <code class="xref py py-class docutils literal notranslate"><span class="pre">FrameSummary</span></code> are captured as object

  632. representations.</p>

  633. <div class="versionchanged">

  634. <p><span class="versionmodified changed">Changed in version 3.12: </span>Exceptions raised from <a class="reference internal" href="functions.html#repr" title="repr"><code class="xref py py-func docutils literal notranslate"><span class="pre">repr()</span></code></a> on a local variable (when

  635. <em>capture_locals</em> is <code class="docutils literal notranslate"><span class="pre">True</span></code>) are no longer propagated to the caller.</p>

  636. </div>

  637. </dd></dl>

  638. 

  639. <dl class="py method">

  640. <dt class="sig sig-object py" id="traceback.StackSummary.from_list">

  641. <em class="property"><span class="pre">classmethod</span><span class="w"> </span></em><span class="sig-name descname"><span class="pre">from_list</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">a_list</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#traceback.StackSummary.from_list" title="Link to this definition">¶</a></dt>

  642. <dd><p>Construct a <code class="xref py py-class docutils literal notranslate"><span class="pre">StackSummary</span></code> object from a supplied list of

  643. <a class="reference internal" href="#traceback.FrameSummary" title="traceback.FrameSummary"><code class="xref py py-class docutils literal notranslate"><span class="pre">FrameSummary</span></code></a> objects or old-style list of tuples.  Each tuple

  644. should be a 4-tuple with <em>filename</em>, <em>lineno</em>, <em>name</em>, <em>line</em> as the

  645. elements.</p>

  646. </dd></dl>

  647. 

  648. <dl class="py method">

  649. <dt class="sig sig-object py" id="traceback.StackSummary.format">

  650. <span class="sig-name descname"><span class="pre">format</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#traceback.StackSummary.format" title="Link to this definition">¶</a></dt>

  651. <dd><p>Returns a list of strings ready for printing.  Each string in the

  652. resulting list corresponds to a single <a class="reference internal" href="../reference/datamodel.html#frame-objects"><span class="std std-ref">frame</span></a> from

  653. the stack.

  654. Each string ends in a newline; the strings may contain internal

  655. newlines as well, for those items with source text lines.</p>

  656. <p>For long sequences of the same frame and line, the first few

  657. repetitions are shown, followed by a summary line stating the exact

  658. number of further repetitions.</p>

  659. <div class="versionchanged">

  660. <p><span class="versionmodified changed">Changed in version 3.6: </span>Long sequences of repeated frames are now abbreviated.</p>

  661. </div>

  662. </dd></dl>

  663. 

  664. <dl class="py method">

  665. <dt class="sig sig-object py" id="traceback.StackSummary.format_frame_summary">

  666. <span class="sig-name descname"><span class="pre">format_frame_summary</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">frame_summary</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#traceback.StackSummary.format_frame_summary" title="Link to this definition">¶</a></dt>

  667. <dd><p>Returns a string for printing one of the <a class="reference internal" href="../reference/datamodel.html#frame-objects"><span class="std std-ref">frames</span></a>

  668. involved in the stack.

  669. This method is called for each <a class="reference internal" href="#traceback.FrameSummary" title="traceback.FrameSummary"><code class="xref py py-class docutils literal notranslate"><span class="pre">FrameSummary</span></code></a> object to be

  670. printed by <a class="reference internal" href="#traceback.StackSummary.format" title="traceback.StackSummary.format"><code class="xref py py-meth docutils literal notranslate"><span class="pre">StackSummary.format()</span></code></a>. If it returns <code class="docutils literal notranslate"><span class="pre">None</span></code>, the

  671. frame is omitted from the output.</p>

  672. <div class="versionadded">

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

  674. </div>

  675. </dd></dl>

  676. 

  677. </dd></dl>

  678. 

  679. </section>

  680. <section id="framesummary-objects">

  681. <h2><code class="xref py py-class docutils literal notranslate"><span class="pre">FrameSummary</span></code> Objects<a class="headerlink" href="#framesummary-objects" title="Link to this heading">¶</a></h2>

  682. <div class="versionadded">

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

  684. </div>

  685. <p>A <code class="xref py py-class docutils literal notranslate"><span class="pre">FrameSummary</span></code> object represents a single <a class="reference internal" href="../reference/datamodel.html#frame-objects"><span class="std std-ref">frame</span></a>

  686. in a <a class="reference internal" href="../reference/datamodel.html#traceback-objects"><span class="std std-ref">traceback</span></a>.</p>

  687. <dl class="py class">

  688. <dt class="sig sig-object py" id="traceback.FrameSummary">

  689. <em class="property"><span class="pre">class</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">traceback.</span></span><span class="sig-name descname"><span class="pre">FrameSummary</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">lineno</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">name</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">lookup_line</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">True</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">locals</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">line</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="#traceback.FrameSummary" title="Link to this definition">¶</a></dt>

  690. <dd><p>Represents a single <a class="reference internal" href="../reference/datamodel.html#frame-objects"><span class="std std-ref">frame</span></a> in the

  691. <a class="reference internal" href="../reference/datamodel.html#traceback-objects"><span class="std std-ref">traceback</span></a> or stack that is being formatted

  692. or printed. It may optionally have a stringified version of the frame’s

  693. locals included in it. If <em>lookup_line</em> is <code class="docutils literal notranslate"><span class="pre">False</span></code>, the source code is not

  694. looked up until the <code class="xref py py-class docutils literal notranslate"><span class="pre">FrameSummary</span></code> has the <a class="reference internal" href="#traceback.FrameSummary.line" title="traceback.FrameSummary.line"><code class="xref py py-attr docutils literal notranslate"><span class="pre">line</span></code></a>

  695. attribute accessed (which also happens when casting it to a <a class="reference internal" href="stdtypes.html#tuple" title="tuple"><code class="xref py py-class docutils literal notranslate"><span class="pre">tuple</span></code></a>).

  696. <a class="reference internal" href="#traceback.FrameSummary.line" title="traceback.FrameSummary.line"><code class="xref py py-attr docutils literal notranslate"><span class="pre">line</span></code></a> may be directly provided, and will prevent line

  697. lookups happening at all. <em>locals</em> is an optional local variable

  698. dictionary, and if supplied the variable representations are stored in the

  699. summary for later display.</p>

  700. <p><code class="xref py py-class docutils literal notranslate"><span class="pre">FrameSummary</span></code> instances have the following attributes:</p>

  701. <dl class="py attribute">

  702. <dt class="sig sig-object py" id="traceback.FrameSummary.filename">

  703. <span class="sig-name descname"><span class="pre">filename</span></span><a class="headerlink" href="#traceback.FrameSummary.filename" title="Link to this definition">¶</a></dt>

  704. <dd><p>The filename of the source code for this frame. Equivalent to accessing

  705. <a class="reference internal" href="../reference/datamodel.html#codeobject.co_filename" title="codeobject.co_filename"><code class="xref py py-attr docutils literal notranslate"><span class="pre">f.f_code.co_filename</span></code></a> on a

  706. <a class="reference internal" href="../reference/datamodel.html#frame-objects"><span class="std std-ref">frame object</span></a> <em>f</em>.</p>

  707. </dd></dl>

  708. 

  709. <dl class="py attribute">

  710. <dt class="sig sig-object py" id="traceback.FrameSummary.lineno">

  711. <span class="sig-name descname"><span class="pre">lineno</span></span><a class="headerlink" href="#traceback.FrameSummary.lineno" title="Link to this definition">¶</a></dt>

  712. <dd><p>The line number of the source code for this frame.</p>

  713. </dd></dl>

  714. 

  715. <dl class="py attribute">

  716. <dt class="sig sig-object py" id="traceback.FrameSummary.name">

  717. <span class="sig-name descname"><span class="pre">name</span></span><a class="headerlink" href="#traceback.FrameSummary.name" title="Link to this definition">¶</a></dt>

  718. <dd><p>Equivalent to accessing <a class="reference internal" href="../reference/datamodel.html#codeobject.co_name" title="codeobject.co_name"><code class="xref py py-attr docutils literal notranslate"><span class="pre">f.f_code.co_name</span></code></a> on

  719. a <a class="reference internal" href="../reference/datamodel.html#frame-objects"><span class="std std-ref">frame object</span></a> <em>f</em>.</p>

  720. </dd></dl>

  721. 

  722. <dl class="py attribute">

  723. <dt class="sig sig-object py" id="traceback.FrameSummary.line">

  724. <span class="sig-name descname"><span class="pre">line</span></span><a class="headerlink" href="#traceback.FrameSummary.line" title="Link to this definition">¶</a></dt>

  725. <dd><p>A string representing the source code for this frame, with leading and

  726. trailing whitespace stripped.

  727. If the source is not available, it is <code class="docutils literal notranslate"><span class="pre">None</span></code>.</p>

  728. </dd></dl>

  729. 

  730. </dd></dl>

  731. 

  732. </section>

  733. <section id="traceback-examples">

  734. <span id="traceback-example"></span><h2>Traceback Examples<a class="headerlink" href="#traceback-examples" title="Link to this heading">¶</a></h2>

  735. <p>This simple example implements a basic read-eval-print loop, similar to (but

  736. less useful than) the standard Python interactive interpreter loop.  For a more

  737. complete implementation of the interpreter loop, refer to the <a class="reference internal" href="code.html#module-code" title="code: Facilities to implement read-eval-print loops."><code class="xref py py-mod docutils literal notranslate"><span class="pre">code</span></code></a>

  738. module.</p>

  739. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">sys</span><span class="o">,</span> <span class="nn">traceback</span>

  740. 

  741. <span class="k">def</span> <span class="nf">run_user_code</span><span class="p">(</span><span class="n">envdir</span><span class="p">):</span>

  742.     <span class="n">source</span> <span class="o">=</span> <span class="nb">input</span><span class="p">(</span><span class="s2">&quot;&gt;&gt;&gt; &quot;</span><span class="p">)</span>

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

  744.         <span class="n">exec</span><span class="p">(</span><span class="n">source</span><span class="p">,</span> <span class="n">envdir</span><span class="p">)</span>

  745.     <span class="k">except</span> <span class="ne">Exception</span><span class="p">:</span>

  746.         <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;Exception in user code:&quot;</span><span class="p">)</span>

  747.         <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;-&quot;</span><span class="o">*</span><span class="mi">60</span><span class="p">)</span>

  748.         <span class="n">traceback</span><span class="o">.</span><span class="n">print_exc</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">stdout</span><span class="p">)</span>

  749.         <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;-&quot;</span><span class="o">*</span><span class="mi">60</span><span class="p">)</span>

  750. 

  751. <span class="n">envdir</span> <span class="o">=</span> <span class="p">{}</span>

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

  753.     <span class="n">run_user_code</span><span class="p">(</span><span class="n">envdir</span><span class="p">)</span>

  754. </pre></div>

  755. </div>

  756. <p>The following example demonstrates the different ways to print and format the

  757. exception and traceback:</p>

  758. <div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">sys</span><span class="o">,</span> <span class="nn">traceback</span>

  759. 

  760. <span class="k">def</span> <span class="nf">lumberjack</span><span class="p">():</span>

  761.     <span class="n">bright_side_of_life</span><span class="p">()</span>

  762. 

  763. <span class="k">def</span> <span class="nf">bright_side_of_life</span><span class="p">():</span>

  764.     <span class="k">return</span> <span class="nb">tuple</span><span class="p">()[</span><span class="mi">0</span><span class="p">]</span>

  765. 

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

  767.     <span class="n">lumberjack</span><span class="p">()</span>

  768. <span class="k">except</span> <span class="ne">IndexError</span><span class="p">:</span>

  769.     <span class="n">exc</span> <span class="o">=</span> <span class="n">sys</span><span class="o">.</span><span class="n">exception</span><span class="p">()</span>

  770.     <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;*** print_tb:&quot;</span><span class="p">)</span>

  771.     <span class="n">traceback</span><span class="o">.</span><span class="n">print_tb</span><span class="p">(</span><span class="n">exc</span><span class="o">.</span><span class="n">__traceback__</span><span class="p">,</span> <span class="n">limit</span><span class="o">=</span><span class="mi">1</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">stdout</span><span class="p">)</span>

  772.     <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;*** print_exception:&quot;</span><span class="p">)</span>

  773.     <span class="n">traceback</span><span class="o">.</span><span class="n">print_exception</span><span class="p">(</span><span class="n">exc</span><span class="p">,</span> <span class="n">limit</span><span class="o">=</span><span class="mi">2</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">stdout</span><span class="p">)</span>

  774.     <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;*** print_exc:&quot;</span><span class="p">)</span>

  775.     <span class="n">traceback</span><span class="o">.</span><span class="n">print_exc</span><span class="p">(</span><span class="n">limit</span><span class="o">=</span><span class="mi">2</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">stdout</span><span class="p">)</span>

  776.     <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;*** format_exc, first and last line:&quot;</span><span class="p">)</span>

  777.     <span class="n">formatted_lines</span> <span class="o">=</span> <span class="n">traceback</span><span class="o">.</span><span class="n">format_exc</span><span class="p">()</span><span class="o">.</span><span class="n">splitlines</span><span class="p">()</span>

  778.     <span class="nb">print</span><span class="p">(</span><span class="n">formatted_lines</span><span class="p">[</span><span class="mi">0</span><span class="p">])</span>

  779.     <span class="nb">print</span><span class="p">(</span><span class="n">formatted_lines</span><span class="p">[</span><span class="o">-</span><span class="mi">1</span><span class="p">])</span>

  780.     <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;*** format_exception:&quot;</span><span class="p">)</span>

  781.     <span class="nb">print</span><span class="p">(</span><span class="nb">repr</span><span class="p">(</span><span class="n">traceback</span><span class="o">.</span><span class="n">format_exception</span><span class="p">(</span><span class="n">exc</span><span class="p">)))</span>

  782.     <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;*** extract_tb:&quot;</span><span class="p">)</span>

  783.     <span class="nb">print</span><span class="p">(</span><span class="nb">repr</span><span class="p">(</span><span class="n">traceback</span><span class="o">.</span><span class="n">extract_tb</span><span class="p">(</span><span class="n">exc</span><span class="o">.</span><span class="n">__traceback__</span><span class="p">)))</span>

  784.     <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;*** format_tb:&quot;</span><span class="p">)</span>

  785.     <span class="nb">print</span><span class="p">(</span><span class="nb">repr</span><span class="p">(</span><span class="n">traceback</span><span class="o">.</span><span class="n">format_tb</span><span class="p">(</span><span class="n">exc</span><span class="o">.</span><span class="n">__traceback__</span><span class="p">)))</span>

  786.     <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;*** tb_lineno:&quot;</span><span class="p">,</span> <span class="n">exc</span><span class="o">.</span><span class="n">__traceback__</span><span class="o">.</span><span class="n">tb_lineno</span><span class="p">)</span>

  787. </pre></div>

  788. </div>

  789. <p>The output for the example would look similar to this:</p>

  790. <div class="highlight-none notranslate"><div class="highlight"><pre><span></span>*** print_tb:

  791.   File &quot;&lt;doctest...&gt;&quot;, line 10, in &lt;module&gt;

  792.     lumberjack()

  793. *** print_exception:

  794. Traceback (most recent call last):

  795.   File &quot;&lt;doctest...&gt;&quot;, line 10, in &lt;module&gt;

  796.     lumberjack()

  797.   File &quot;&lt;doctest...&gt;&quot;, line 4, in lumberjack

  798.     bright_side_of_life()

  799. IndexError: tuple index out of range

  800. *** print_exc:

  801. Traceback (most recent call last):

  802.   File &quot;&lt;doctest...&gt;&quot;, line 10, in &lt;module&gt;

  803.     lumberjack()

  804.   File &quot;&lt;doctest...&gt;&quot;, line 4, in lumberjack

  805.     bright_side_of_life()

  806. IndexError: tuple index out of range

  807. *** format_exc, first and last line:

  808. Traceback (most recent call last):

  809. IndexError: tuple index out of range

  810. *** format_exception:

  811. [&#39;Traceback (most recent call last):\n&#39;,

  812.  &#39;  File &quot;&lt;doctest default[0]&gt;&quot;, line 10, in &lt;module&gt;\n    lumberjack()\n&#39;,

  813.  &#39;  File &quot;&lt;doctest default[0]&gt;&quot;, line 4, in lumberjack\n    bright_side_of_life()\n&#39;,

  814.  &#39;  File &quot;&lt;doctest default[0]&gt;&quot;, line 7, in bright_side_of_life\n    return tuple()[0]\n           ~~~~~~~^^^\n&#39;,

  815.  &#39;IndexError: tuple index out of range\n&#39;]

  816. *** extract_tb:

  817. [&lt;FrameSummary file &lt;doctest...&gt;, line 10 in &lt;module&gt;&gt;,

  818.  &lt;FrameSummary file &lt;doctest...&gt;, line 4 in lumberjack&gt;,

  819.  &lt;FrameSummary file &lt;doctest...&gt;, line 7 in bright_side_of_life&gt;]

  820. *** format_tb:

  821. [&#39;  File &quot;&lt;doctest default[0]&gt;&quot;, line 10, in &lt;module&gt;\n    lumberjack()\n&#39;,

  822.  &#39;  File &quot;&lt;doctest default[0]&gt;&quot;, line 4, in lumberjack\n    bright_side_of_life()\n&#39;,

  823.  &#39;  File &quot;&lt;doctest default[0]&gt;&quot;, line 7, in bright_side_of_life\n    return tuple()[0]\n           ~~~~~~~^^^\n&#39;]

  824. *** tb_lineno: 10

  825. </pre></div>

  826. </div>

  827. <p>The following example shows the different ways to print and format the stack:</p>

  828. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">import</span> <span class="nn">traceback</span>

  829. <span class="gp">&gt;&gt;&gt; </span><span class="k">def</span> <span class="nf">another_function</span><span class="p">():</span>

  830. <span class="gp">... </span>    <span class="n">lumberstack</span><span class="p">()</span>

  831. <span class="gp">...</span>

  832. <span class="gp">&gt;&gt;&gt; </span><span class="k">def</span> <span class="nf">lumberstack</span><span class="p">():</span>

  833. <span class="gp">... </span>    <span class="n">traceback</span><span class="o">.</span><span class="n">print_stack</span><span class="p">()</span>

  834. <span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="nb">repr</span><span class="p">(</span><span class="n">traceback</span><span class="o">.</span><span class="n">extract_stack</span><span class="p">()))</span>

  835. <span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="nb">repr</span><span class="p">(</span><span class="n">traceback</span><span class="o">.</span><span class="n">format_stack</span><span class="p">()))</span>

  836. <span class="gp">...</span>

  837. <span class="gp">&gt;&gt;&gt; </span><span class="n">another_function</span><span class="p">()</span>

  838.   File <span class="nb">&quot;&lt;doctest&gt;&quot;</span>, line <span class="m">10</span>, in <span class="n">&lt;module&gt;</span>

  839. <span class="w">    </span><span class="n">another_function</span><span class="p">()</span>

  840.   File <span class="nb">&quot;&lt;doctest&gt;&quot;</span>, line <span class="m">3</span>, in <span class="n">another_function</span>

  841. <span class="w">    </span><span class="n">lumberstack</span><span class="p">()</span>

  842.   File <span class="nb">&quot;&lt;doctest&gt;&quot;</span>, line <span class="m">6</span>, in <span class="n">lumberstack</span>

  843. <span class="w">    </span><span class="n">traceback</span><span class="o">.</span><span class="n">print_stack</span><span class="p">()</span>

  844. <span class="x">[(&#39;&lt;doctest&gt;&#39;, 10, &#39;&lt;module&gt;&#39;, &#39;another_function()&#39;),</span>

  845. <span class="x"> (&#39;&lt;doctest&gt;&#39;, 3, &#39;another_function&#39;, &#39;lumberstack()&#39;),</span>

  846. <span class="x"> (&#39;&lt;doctest&gt;&#39;, 7, &#39;lumberstack&#39;, &#39;print(repr(traceback.extract_stack()))&#39;)]</span>

  847. <span class="x">[&#39;  File &quot;&lt;doctest&gt;&quot;, line 10, in &lt;module&gt;\n    another_function()\n&#39;,</span>

  848. <span class="x"> &#39;  File &quot;&lt;doctest&gt;&quot;, line 3, in another_function\n    lumberstack()\n&#39;,</span>

  849. <span class="x"> &#39;  File &quot;&lt;doctest&gt;&quot;, line 8, in lumberstack\n    print(repr(traceback.format_stack()))\n&#39;]</span>

  850. </pre></div>

  851. </div>

  852. <p>This last example demonstrates the final few formatting functions:</p>

  853. <div class="highlight-pycon notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">import</span> <span class="nn">traceback</span>

  854. <span class="gp">&gt;&gt;&gt; </span><span class="n">traceback</span><span class="o">.</span><span class="n">format_list</span><span class="p">([(</span><span class="s1">&#39;spam.py&#39;</span><span class="p">,</span> <span class="mi">3</span><span class="p">,</span> <span class="s1">&#39;&lt;module&gt;&#39;</span><span class="p">,</span> <span class="s1">&#39;spam.eggs()&#39;</span><span class="p">),</span>

  855. <span class="gp">... </span>                       <span class="p">(</span><span class="s1">&#39;eggs.py&#39;</span><span class="p">,</span> <span class="mi">42</span><span class="p">,</span> <span class="s1">&#39;eggs&#39;</span><span class="p">,</span> <span class="s1">&#39;return &quot;bacon&quot;&#39;</span><span class="p">)])</span>

  856. <span class="go">[&#39;  File &quot;spam.py&quot;, line 3, in &lt;module&gt;\n    spam.eggs()\n&#39;,</span>

  857. <span class="go"> &#39;  File &quot;eggs.py&quot;, line 42, in eggs\n    return &quot;bacon&quot;\n&#39;]</span>

  858. <span class="gp">&gt;&gt;&gt; </span><span class="n">an_error</span> <span class="o">=</span> <span class="ne">IndexError</span><span class="p">(</span><span class="s1">&#39;tuple index out of range&#39;</span><span class="p">)</span>

  859. <span class="gp">&gt;&gt;&gt; </span><span class="n">traceback</span><span class="o">.</span><span class="n">format_exception_only</span><span class="p">(</span><span class="nb">type</span><span class="p">(</span><span class="n">an_error</span><span class="p">),</span> <span class="n">an_error</span><span class="p">)</span>

  860. <span class="go">[&#39;IndexError: tuple index out of range\n&#39;]</span>

  861. </pre></div>

  862. </div>

  863. </section>

  864. </section>

  865. 

  866. 

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

  868.           </div>

  869.         </div>

  870.       </div>

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

  872.         <div class="sphinxsidebarwrapper">

  873.   <div>

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

  875.     <ul>

  876. <li><a class="reference internal" href="#"><code class="xref py py-mod docutils literal notranslate"><span class="pre">traceback</span></code> — Print or retrieve a stack traceback</a><ul>

  877. <li><a class="reference internal" href="#tracebackexception-objects"><code class="xref py py-class docutils literal notranslate"><span class="pre">TracebackException</span></code> Objects</a></li>

  878. <li><a class="reference internal" href="#stacksummary-objects"><code class="xref py py-class docutils literal notranslate"><span class="pre">StackSummary</span></code> Objects</a></li>

  879. <li><a class="reference internal" href="#framesummary-objects"><code class="xref py py-class docutils literal notranslate"><span class="pre">FrameSummary</span></code> Objects</a></li>

  880. <li><a class="reference internal" href="#traceback-examples">Traceback Examples</a></li>

  881. </ul>

  882. </li>

  883. </ul>

  884. 

  885.   </div>

  886.   <div>

  887.     <h4>Previous topic</h4>

  888.     <p class="topless"><a href="atexit.html"

  889.                           title="previous chapter"><code class="xref py py-mod docutils literal notranslate"><span class="pre">atexit</span></code> — Exit handlers</a></p>

  890.   </div>

  891.   <div>

  892.     <h4>Next topic</h4>

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

  894.                           title="next chapter"><code class="xref py py-mod docutils literal notranslate"><span class="pre">__future__</span></code> — Future statement definitions</a></p>

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