gooderp18绿色标准版
Nie możesz wybrać więcej, niż 25 tematów Tematy muszą się zaczynać od litery lub cyfry, mogą zawierać myślniki ('-') i mogą mieć do 35 znaków.

1003 lines
91KB

  1. <!DOCTYPE html>
  2. <html lang="en" data-content_root="../">
  3. <head>
  4. <meta charset="utf-8" />
  5. <meta name="viewport" content="width=device-width, initial-scale=1.0" /><meta name="viewport" content="width=device-width, initial-scale=1" />
  6. <meta property="og:title" content="traceback — Print or retrieve a stack traceback" />
  7. <meta property="og:type" content="website" />
  8. <meta property="og:url" content="https://docs.python.org/3/library/traceback.html" />
  9. <meta property="og:site_name" content="Python documentation" />
  10. <meta property="og:description" content="Source code: Lib/traceback.py This module provides a standard interface to extract, format and print stack traces of Python programs. It exactly mimics the behavior of the Python interpreter when i..." />
  11. <meta property="og:image" content="https://docs.python.org/3/_static/og-image.png" />
  12. <meta property="og:image:alt" content="Python documentation" />
  13. <meta name="description" content="Source code: Lib/traceback.py This module provides a standard interface to extract, format and print stack traces of Python programs. It exactly mimics the behavior of the Python interpreter when i..." />
  14. <meta property="og:image:width" content="200" />
  15. <meta property="og:image:height" content="200" />
  16. <meta name="theme-color" content="#3776ab" />
  17. <title>traceback — Print or retrieve a stack traceback &#8212; Python 3.12.3 documentation</title><meta name="viewport" content="width=device-width, initial-scale=1.0">
  18. <link rel="stylesheet" type="text/css" href="../_static/pygments.css?v=80d5e7a1" />
  19. <link rel="stylesheet" type="text/css" href="../_static/pydoctheme.css?v=bb723527" />
  20. <link id="pygments_dark_css" media="(prefers-color-scheme: dark)" rel="stylesheet" type="text/css" href="../_static/pygments_dark.css?v=b20cc3f5" />
  21. <script src="../_static/documentation_options.js?v=2c828074"></script>
  22. <script src="../_static/doctools.js?v=888ff710"></script>
  23. <script src="../_static/sphinx_highlight.js?v=dc90522c"></script>
  24. <script src="../_static/sidebar.js"></script>
  25. <link rel="search" type="application/opensearchdescription+xml"
  26. title="Search within Python 3.12.3 documentation"
  27. href="../_static/opensearch.xml"/>
  28. <link rel="author" title="About these documents" href="../about.html" />
  29. <link rel="index" title="Index" href="../genindex.html" />
  30. <link rel="search" title="Search" href="../search.html" />
  31. <link rel="copyright" title="Copyright" href="../copyright.html" />
  32. <link rel="next" title="__future__ — Future statement definitions" href="__future__.html" />
  33. <link rel="prev" title="atexit — Exit handlers" href="atexit.html" />
  34. <link rel="canonical" href="https://docs.python.org/3/library/traceback.html" />
  35. <style>
  36. @media only screen {
  37. table.full-width-table {
  38. width: 100%;
  39. }
  40. }
  41. </style>
  42. <link rel="stylesheet" href="../_static/pydoctheme_dark.css" media="(prefers-color-scheme: dark)" id="pydoctheme_dark_css">
  43. <link rel="shortcut icon" type="image/png" href="../_static/py.svg" />
  44. <script type="text/javascript" src="../_static/copybutton.js"></script>
  45. <script type="text/javascript" src="../_static/menu.js"></script>
  46. <script type="text/javascript" src="../_static/search-focus.js"></script>
  47. <script type="text/javascript" src="../_static/themetoggle.js"></script>
  48. </head>
  49. <body>
  50. <div class="mobile-nav">
  51. <input type="checkbox" id="menuToggler" class="toggler__input" aria-controls="navigation"
  52. aria-pressed="false" aria-expanded="false" role="button" aria-label="Menu" />
  53. <nav class="nav-content" role="navigation">
  54. <label for="menuToggler" class="toggler__label">
  55. <span></span>
  56. </label>
  57. <span class="nav-items-wrapper">
  58. <a href="https://www.python.org/" class="nav-logo">
  59. <img src="../_static/py.svg" alt="Python logo"/>
  60. </a>
  61. <span class="version_switcher_placeholder"></span>
  62. <form role="search" class="search" action="../search.html" method="get">
  63. <svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" class="search-icon">
  64. <path fill-rule="nonzero" fill="currentColor" d="M15.5 14h-.79l-.28-.27a6.5 6.5 0 001.48-5.34c-.47-2.78-2.79-5-5.59-5.34a6.505 6.505 0 00-7.27 7.27c.34 2.8 2.56 5.12 5.34 5.59a6.5 6.5 0 005.34-1.48l.27.28v.79l4.25 4.25c.41.41 1.08.41 1.49 0 .41-.41.41-1.08 0-1.49L15.5 14zm-6 0C7.01 14 5 11.99 5 9.5S7.01 5 9.5 5 14 7.01 14 9.5 11.99 14 9.5 14z"></path>
  65. </svg>
  66. <input placeholder="Quick search" aria-label="Quick search" type="search" name="q" />
  67. <input type="submit" value="Go"/>
  68. </form>
  69. </span>
  70. </nav>
  71. <div class="menu-wrapper">
  72. <nav class="menu" role="navigation" aria-label="main navigation">
  73. <div class="language_switcher_placeholder"></div>
  74. <label class="theme-selector-label">
  75. Theme
  76. <select class="theme-selector" oninput="activateTheme(this.value)">
  77. <option value="auto" selected>Auto</option>
  78. <option value="light">Light</option>
  79. <option value="dark">Dark</option>
  80. </select>
  81. </label>
  82. <div>
  83. <h3><a href="../contents.html">Table of Contents</a></h3>
  84. <ul>
  85. <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>
  86. <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>
  87. <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>
  88. <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>
  89. <li><a class="reference internal" href="#traceback-examples">Traceback Examples</a></li>
  90. </ul>
  91. </li>
  92. </ul>
  93. </div>
  94. <div>
  95. <h4>Previous topic</h4>
  96. <p class="topless"><a href="atexit.html"
  97. title="previous chapter"><code class="xref py py-mod docutils literal notranslate"><span class="pre">atexit</span></code> — Exit handlers</a></p>
  98. </div>
  99. <div>
  100. <h4>Next topic</h4>
  101. <p class="topless"><a href="__future__.html"
  102. title="next chapter"><code class="xref py py-mod docutils literal notranslate"><span class="pre">__future__</span></code> — Future statement definitions</a></p>
  103. </div>
  104. <div role="note" aria-label="source link">
  105. <h3>This Page</h3>
  106. <ul class="this-page-menu">
  107. <li><a href="../bugs.html">Report a Bug</a></li>
  108. <li>
  109. <a href="https://github.com/python/cpython/blob/main/Doc/library/traceback.rst"
  110. rel="nofollow">Show Source
  111. </a>
  112. </li>
  113. </ul>
  114. </div>
  115. </nav>
  116. </div>
  117. </div>
  118. <div class="related" role="navigation" aria-label="related navigation">
  119. <h3>Navigation</h3>
  120. <ul>
  121. <li class="right" style="margin-right: 10px">
  122. <a href="../genindex.html" title="General Index"
  123. accesskey="I">index</a></li>
  124. <li class="right" >
  125. <a href="../py-modindex.html" title="Python Module Index"
  126. >modules</a> |</li>
  127. <li class="right" >
  128. <a href="__future__.html" title="__future__ — Future statement definitions"
  129. accesskey="N">next</a> |</li>
  130. <li class="right" >
  131. <a href="atexit.html" title="atexit — Exit handlers"
  132. accesskey="P">previous</a> |</li>
  133. <li><img src="../_static/py.svg" alt="Python logo" style="vertical-align: middle; margin-top: -1px"/></li>
  134. <li><a href="https://www.python.org/">Python</a> &#187;</li>
  135. <li class="switchers">
  136. <div class="language_switcher_placeholder"></div>
  137. <div class="version_switcher_placeholder"></div>
  138. </li>
  139. <li>
  140. </li>
  141. <li id="cpython-language-and-version">
  142. <a href="../index.html">3.12.3 Documentation</a> &#187;
  143. </li>
  144. <li class="nav-item nav-item-1"><a href="index.html" >The Python Standard Library</a> &#187;</li>
  145. <li class="nav-item nav-item-2"><a href="python.html" accesskey="U">Python Runtime Services</a> &#187;</li>
  146. <li class="nav-item nav-item-this"><a href=""><code class="xref py py-mod docutils literal notranslate"><span class="pre">traceback</span></code> — Print or retrieve a stack traceback</a></li>
  147. <li class="right">
  148. <div class="inline-search" role="search">
  149. <form class="inline-search" action="../search.html" method="get">
  150. <input placeholder="Quick search" aria-label="Quick search" type="search" name="q" id="search-box" />
  151. <input type="submit" value="Go" />
  152. </form>
  153. </div>
  154. |
  155. </li>
  156. <li class="right">
  157. <label class="theme-selector-label">
  158. Theme
  159. <select class="theme-selector" oninput="activateTheme(this.value)">
  160. <option value="auto" selected>Auto</option>
  161. <option value="light">Light</option>
  162. <option value="dark">Dark</option>
  163. </select>
  164. </label> |</li>
  165. </ul>
  166. </div>
  167. <div class="document">
  168. <div class="documentwrapper">
  169. <div class="bodywrapper">
  170. <div class="body" role="main">
  171. <section id="module-traceback">
  172. <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>
  173. <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>
  174. <hr class="docutils" />
  175. <p>This module provides a standard interface to extract, format and print stack
  176. traces of Python programs. It exactly mimics the behavior of the Python
  177. interpreter when it prints a stack trace. This is useful when you want to print
  178. stack traces under program control, such as in a “wrapper” around the
  179. interpreter.</p>
  180. <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
  181. 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>,
  182. 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
  183. <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>
  184. <div class="admonition seealso">
  185. <p class="admonition-title">See also</p>
  186. <dl class="simple">
  187. <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>
  188. </dd>
  189. <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>
  190. </dd>
  191. </dl>
  192. </div>
  193. <p>The module defines the following functions:</p>
  194. <dl class="py function">
  195. <dt class="sig sig-object py" id="traceback.print_tb">
  196. <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>
  197. <dd><p>Print up to <em>limit</em> stack trace entries from
  198. <a class="reference internal" href="../reference/datamodel.html#traceback-objects"><span class="std std-ref">traceback object</span></a> <em>tb</em> (starting
  199. from the caller’s frame) if <em>limit</em> is positive. Otherwise, print the last
  200. <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
  201. printed. If <em>file</em> is omitted or <code class="docutils literal notranslate"><span class="pre">None</span></code>, the output goes to
  202. <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
  203. <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
  204. receive the output.</p>
  205. <div class="versionchanged">
  206. <p><span class="versionmodified changed">Changed in version 3.5: </span>Added negative <em>limit</em> support.</p>
  207. </div>
  208. </dd></dl>
  209. <dl class="py function">
  210. <dt class="sig sig-object py" id="traceback.print_exception">
  211. <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>
  212. <dd><p>Print exception information and stack trace entries from
  213. <a class="reference internal" href="../reference/datamodel.html#traceback-objects"><span class="std std-ref">traceback object</span></a>
  214. <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
  215. ways:</p>
  216. <ul class="simple">
  217. <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>
  218. <span class="pre">call</span> <span class="pre">last):</span></code></p></li>
  219. <li><p>it prints the exception type and <em>value</em> after the stack trace</p></li>
  220. </ul>
  221. <ul class="simple" id="index-1">
  222. <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
  223. format, it prints the line where the syntax error occurred with a caret
  224. indicating the approximate position of the error.</p></li>
  225. </ul>
  226. <p>Since Python 3.10, instead of passing <em>value</em> and <em>tb</em>, an exception object
  227. can be passed as the first argument. If <em>value</em> and <em>tb</em> are provided, the
  228. first argument is ignored in order to provide backwards compatibility.</p>
  229. <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>.
  230. If <em>chain</em> is true (the default), then chained exceptions (the
  231. <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>
  232. attributes of the exception) will be
  233. printed as well, like the interpreter itself does when printing an unhandled
  234. exception.</p>
  235. <div class="versionchanged">
  236. <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>
  237. </div>
  238. <div class="versionchanged">
  239. <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
  240. positional-only.</p>
  241. </div>
  242. </dd></dl>
  243. <dl class="py function">
  244. <dt class="sig sig-object py" id="traceback.print_exc">
  245. <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>
  246. <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>
  247. <span class="pre">chain)</span></code>.</p>
  248. </dd></dl>
  249. <dl class="py function">
  250. <dt class="sig sig-object py" id="traceback.print_last">
  251. <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>
  252. <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>
  253. <span class="pre">chain)</span></code>. In general it will work only after an exception has reached
  254. 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>
  255. </dd></dl>
  256. <dl class="py function">
  257. <dt class="sig sig-object py" id="traceback.print_stack">
  258. <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>
  259. <dd><p>Print up to <em>limit</em> stack trace entries (starting from the invocation
  260. point) if <em>limit</em> is positive. Otherwise, print the last <code class="docutils literal notranslate"><span class="pre">abs(limit)</span></code>
  261. entries. If <em>limit</em> is omitted or <code class="docutils literal notranslate"><span class="pre">None</span></code>, all entries are printed.
  262. The optional <em>f</em> argument can be used to specify an alternate
  263. <a class="reference internal" href="../reference/datamodel.html#frame-objects"><span class="std std-ref">stack frame</span></a>
  264. to start. The optional <em>file</em> argument has the same meaning as for
  265. <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>
  266. <div class="versionchanged">
  267. <p><span class="versionmodified changed">Changed in version 3.5: </span>Added negative <em>limit</em> support.</p>
  268. </div>
  269. </dd></dl>
  270. <dl class="py function">
  271. <dt class="sig sig-object py" id="traceback.extract_tb">
  272. <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>
  273. <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”
  274. stack trace entries extracted from the
  275. <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
  276. for alternate formatting of stack traces. The optional <em>limit</em> argument has
  277. 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
  278. 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
  279. <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>,
  280. <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
  281. information that is usually printed for a stack trace.</p>
  282. </dd></dl>
  283. <dl class="py function">
  284. <dt class="sig sig-object py" id="traceback.extract_stack">
  285. <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>
  286. <dd><p>Extract the raw traceback from the current
  287. <a class="reference internal" href="../reference/datamodel.html#frame-objects"><span class="std std-ref">stack frame</span></a>. The return value has
  288. 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>
  289. 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>
  290. </dd></dl>
  291. <dl class="py function">
  292. <dt class="sig sig-object py" id="traceback.format_list">
  293. <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>
  294. <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
  295. <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
  296. for printing. Each string in the resulting list corresponds to the item with
  297. the same index in the argument list. Each string ends in a newline; the
  298. strings may contain internal newlines as well, for those items whose source
  299. text line is not <code class="docutils literal notranslate"><span class="pre">None</span></code>.</p>
  300. </dd></dl>
  301. <dl class="py function">
  302. <dt class="sig sig-object py" id="traceback.format_exception_only">
  303. <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>
  304. <dd><p>Format the exception part of a traceback using an exception value such as
  305. 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
  306. ending in a newline. The list contains the exception’s message, which is
  307. 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
  308. contains several lines that (when printed) display detailed information
  309. about where the syntax error occurred. Following the message, the list
  310. 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>
  311. <p>Since Python 3.10, instead of passing <em>value</em>, an exception object
  312. can be passed as the first argument. If <em>value</em> is provided, the first
  313. argument is ignored in order to provide backwards compatibility.</p>
  314. <div class="versionchanged">
  315. <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
  316. positional-only.</p>
  317. </div>
  318. <div class="versionchanged">
  319. <p><span class="versionmodified changed">Changed in version 3.11: </span>The returned list now includes any
  320. <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>
  321. </div>
  322. </dd></dl>
  323. <dl class="py function">
  324. <dt class="sig sig-object py" id="traceback.format_exception">
  325. <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>
  326. <dd><p>Format a stack trace and the exception information. The arguments have the
  327. 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
  328. return value is a list of strings, each ending in a newline and some
  329. containing internal newlines. When these lines are concatenated and printed,
  330. 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>
  331. <div class="versionchanged">
  332. <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>
  333. </div>
  334. <div class="versionchanged">
  335. <p><span class="versionmodified changed">Changed in version 3.10: </span>This function’s behavior and signature were modified to match
  336. <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>
  337. </div>
  338. </dd></dl>
  339. <dl class="py function">
  340. <dt class="sig sig-object py" id="traceback.format_exc">
  341. <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>
  342. <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
  343. a file.</p>
  344. </dd></dl>
  345. <dl class="py function">
  346. <dt class="sig sig-object py" id="traceback.format_tb">
  347. <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>
  348. <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>
  349. </dd></dl>
  350. <dl class="py function">
  351. <dt class="sig sig-object py" id="traceback.format_stack">
  352. <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>
  353. <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>
  354. </dd></dl>
  355. <dl class="py function">
  356. <dt class="sig sig-object py" id="traceback.clear_frames">
  357. <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>
  358. <dd><p>Clears the local variables of all the stack frames in a
  359. <a class="reference internal" href="../reference/datamodel.html#traceback-objects"><span class="std std-ref">traceback</span></a> <em>tb</em>
  360. 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
  361. <a class="reference internal" href="../reference/datamodel.html#frame-objects"><span class="std std-ref">frame object</span></a>.</p>
  362. <div class="versionadded">
  363. <p><span class="versionmodified added">New in version 3.4.</span></p>
  364. </div>
  365. </dd></dl>
  366. <dl class="py function">
  367. <dt class="sig sig-object py" id="traceback.walk_stack">
  368. <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>
  369. <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,
  370. yielding the frame
  371. 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
  372. 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>
  373. <div class="versionadded">
  374. <p><span class="versionmodified added">New in version 3.5.</span></p>
  375. </div>
  376. </dd></dl>
  377. <dl class="py function">
  378. <dt class="sig sig-object py" id="traceback.walk_tb">
  379. <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>
  380. <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
  381. line number
  382. 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>
  383. <div class="versionadded">
  384. <p><span class="versionmodified added">New in version 3.5.</span></p>
  385. </div>
  386. </dd></dl>
  387. <p>The module also defines the following classes:</p>
  388. <section id="tracebackexception-objects">
  389. <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>
  390. <div class="versionadded">
  391. <p><span class="versionmodified added">New in version 3.5.</span></p>
  392. </div>
  393. <p><code class="xref py py-class docutils literal notranslate"><span class="pre">TracebackException</span></code> objects are created from actual exceptions to
  394. capture data for later printing in a lightweight fashion.</p>
  395. <dl class="py class">
  396. <dt class="sig sig-object py" id="traceback.TracebackException">
  397. <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>
  398. <dd><p>Capture an exception for later rendering. <em>limit</em>, <em>lookup_lines</em> and
  399. <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>
  400. <p>If <em>compact</em> is true, only data that is required by
  401. <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
  402. is saved in the class attributes. In particular, the
  403. <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
  404. <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>
  405. <p>Note that when locals are captured, they are also shown in the traceback.</p>
  406. <p><em>max_group_width</em> and <em>max_group_depth</em> control the formatting of exception
  407. 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
  408. level of the group, and the width refers to the size of a single exception
  409. group’s exceptions array. The formatted output is truncated when either
  410. limit is exceeded.</p>
  411. <div class="versionchanged">
  412. <p><span class="versionmodified changed">Changed in version 3.10: </span>Added the <em>compact</em> parameter.</p>
  413. </div>
  414. <div class="versionchanged">
  415. <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>
  416. </div>
  417. <dl class="py attribute">
  418. <dt class="sig sig-object py" id="traceback.TracebackException.__cause__">
  419. <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>
  420. <dd><p>A <code class="xref py py-class docutils literal notranslate"><span class="pre">TracebackException</span></code> of the original
  421. <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>
  422. </dd></dl>
  423. <dl class="py attribute">
  424. <dt class="sig sig-object py" id="traceback.TracebackException.__context__">
  425. <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>
  426. <dd><p>A <code class="xref py py-class docutils literal notranslate"><span class="pre">TracebackException</span></code> of the original
  427. <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>
  428. </dd></dl>
  429. <dl class="py attribute">
  430. <dt class="sig sig-object py" id="traceback.TracebackException.exceptions">
  431. <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>
  432. <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
  433. <code class="xref py py-class docutils literal notranslate"><span class="pre">TracebackException</span></code> instances representing the nested exceptions.
  434. Otherwise it is <code class="docutils literal notranslate"><span class="pre">None</span></code>.</p>
  435. <div class="versionadded">
  436. <p><span class="versionmodified added">New in version 3.11.</span></p>
  437. </div>
  438. </dd></dl>
  439. <dl class="py attribute">
  440. <dt class="sig sig-object py" id="traceback.TracebackException.__suppress_context__">
  441. <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>
  442. <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
  443. exception.</p>
  444. </dd></dl>
  445. <dl class="py attribute">
  446. <dt class="sig sig-object py" id="traceback.TracebackException.__notes__">
  447. <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>
  448. <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,
  449. or <code class="docutils literal notranslate"><span class="pre">None</span></code>
  450. if the exception does not have any notes. If it is not <code class="docutils literal notranslate"><span class="pre">None</span></code>
  451. is it formatted in the traceback after the exception string.</p>
  452. <div class="versionadded">
  453. <p><span class="versionmodified added">New in version 3.11.</span></p>
  454. </div>
  455. </dd></dl>
  456. <dl class="py attribute">
  457. <dt class="sig sig-object py" id="traceback.TracebackException.stack">
  458. <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>
  459. <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>
  460. </dd></dl>
  461. <dl class="py attribute">
  462. <dt class="sig sig-object py" id="traceback.TracebackException.exc_type">
  463. <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>
  464. <dd><p>The class of the original traceback.</p>
  465. </dd></dl>
  466. <dl class="py attribute">
  467. <dt class="sig sig-object py" id="traceback.TracebackException.filename">
  468. <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>
  469. <dd><p>For syntax errors - the file name where the error occurred.</p>
  470. </dd></dl>
  471. <dl class="py attribute">
  472. <dt class="sig sig-object py" id="traceback.TracebackException.lineno">
  473. <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>
  474. <dd><p>For syntax errors - the line number where the error occurred.</p>
  475. </dd></dl>
  476. <dl class="py attribute">
  477. <dt class="sig sig-object py" id="traceback.TracebackException.end_lineno">
  478. <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>
  479. <dd><p>For syntax errors - the end line number where the error occurred.
  480. Can be <code class="docutils literal notranslate"><span class="pre">None</span></code> if not present.</p>
  481. <div class="versionadded">
  482. <p><span class="versionmodified added">New in version 3.10.</span></p>
  483. </div>
  484. </dd></dl>
  485. <dl class="py attribute">
  486. <dt class="sig sig-object py" id="traceback.TracebackException.text">
  487. <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>
  488. <dd><p>For syntax errors - the text where the error occurred.</p>
  489. </dd></dl>
  490. <dl class="py attribute">
  491. <dt class="sig sig-object py" id="traceback.TracebackException.offset">
  492. <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>
  493. <dd><p>For syntax errors - the offset into the text where the error occurred.</p>
  494. </dd></dl>
  495. <dl class="py attribute">
  496. <dt class="sig sig-object py" id="traceback.TracebackException.end_offset">
  497. <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>
  498. <dd><p>For syntax errors - the end offset into the text where the error occurred.
  499. Can be <code class="docutils literal notranslate"><span class="pre">None</span></code> if not present.</p>
  500. <div class="versionadded">
  501. <p><span class="versionmodified added">New in version 3.10.</span></p>
  502. </div>
  503. </dd></dl>
  504. <dl class="py attribute">
  505. <dt class="sig sig-object py" id="traceback.TracebackException.msg">
  506. <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>
  507. <dd><p>For syntax errors - the compiler error message.</p>
  508. </dd></dl>
  509. <dl class="py method">
  510. <dt class="sig sig-object py" id="traceback.TracebackException.from_exception">
  511. <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>
  512. <dd><p>Capture an exception for later rendering. <em>limit</em>, <em>lookup_lines</em> and
  513. <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>
  514. <p>Note that when locals are captured, they are also shown in the traceback.</p>
  515. </dd></dl>
  516. <dl class="py method">
  517. <dt class="sig sig-object py" id="traceback.TracebackException.print">
  518. <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>
  519. <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
  520. <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>
  521. <div class="versionadded">
  522. <p><span class="versionmodified added">New in version 3.11.</span></p>
  523. </div>
  524. </dd></dl>
  525. <dl class="py method">
  526. <dt class="sig sig-object py" id="traceback.TracebackException.format">
  527. <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>
  528. <dd><p>Format the exception.</p>
  529. <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>
  530. will not be formatted.</p>
  531. <p>The return value is a generator of strings, each ending in a newline and
  532. 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>
  533. is a wrapper around this method which just prints the lines to a file.</p>
  534. </dd></dl>
  535. <dl class="py method">
  536. <dt class="sig sig-object py" id="traceback.TracebackException.format_exception_only">
  537. <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>
  538. <dd><p>Format the exception part of the traceback.</p>
  539. <p>The return value is a generator of strings, each ending in a newline.</p>
  540. <p>The generator emits the exception’s message followed by its notes
  541. (if it has any). The exception message is normally a single string;
  542. 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
  543. lines that (when printed) display detailed information about where
  544. the syntax error occurred.</p>
  545. <div class="versionchanged">
  546. <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
  547. included in the output.</p>
  548. </div>
  549. </dd></dl>
  550. </dd></dl>
  551. </section>
  552. <section id="stacksummary-objects">
  553. <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>
  554. <div class="versionadded">
  555. <p><span class="versionmodified added">New in version 3.5.</span></p>
  556. </div>
  557. <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>
  558. <dl class="py class">
  559. <dt class="sig sig-object py" id="traceback.StackSummary">
  560. <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>
  561. <dd><dl class="py method">
  562. <dt class="sig sig-object py" id="traceback.StackSummary.extract">
  563. <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>
  564. <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
  565. 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
  566. <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>
  567. <p>If <em>limit</em> is supplied, only this many frames are taken from <em>frame_gen</em>.
  568. 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>
  569. objects will not have read their lines in yet, making the cost of
  570. creating the <code class="xref py py-class docutils literal notranslate"><span class="pre">StackSummary</span></code> cheaper (which may be valuable if it
  571. may not actually get formatted). If <em>capture_locals</em> is <code class="docutils literal notranslate"><span class="pre">True</span></code> the
  572. local variables in each <code class="xref py py-class docutils literal notranslate"><span class="pre">FrameSummary</span></code> are captured as object
  573. representations.</p>
  574. <div class="versionchanged">
  575. <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
  576. <em>capture_locals</em> is <code class="docutils literal notranslate"><span class="pre">True</span></code>) are no longer propagated to the caller.</p>
  577. </div>
  578. </dd></dl>
  579. <dl class="py method">
  580. <dt class="sig sig-object py" id="traceback.StackSummary.from_list">
  581. <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>
  582. <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
  583. <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
  584. should be a 4-tuple with <em>filename</em>, <em>lineno</em>, <em>name</em>, <em>line</em> as the
  585. elements.</p>
  586. </dd></dl>
  587. <dl class="py method">
  588. <dt class="sig sig-object py" id="traceback.StackSummary.format">
  589. <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>
  590. <dd><p>Returns a list of strings ready for printing. Each string in the
  591. 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
  592. the stack.
  593. Each string ends in a newline; the strings may contain internal
  594. newlines as well, for those items with source text lines.</p>
  595. <p>For long sequences of the same frame and line, the first few
  596. repetitions are shown, followed by a summary line stating the exact
  597. number of further repetitions.</p>
  598. <div class="versionchanged">
  599. <p><span class="versionmodified changed">Changed in version 3.6: </span>Long sequences of repeated frames are now abbreviated.</p>
  600. </div>
  601. </dd></dl>
  602. <dl class="py method">
  603. <dt class="sig sig-object py" id="traceback.StackSummary.format_frame_summary">
  604. <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>
  605. <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>
  606. involved in the stack.
  607. 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
  608. 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
  609. frame is omitted from the output.</p>
  610. <div class="versionadded">
  611. <p><span class="versionmodified added">New in version 3.11.</span></p>
  612. </div>
  613. </dd></dl>
  614. </dd></dl>
  615. </section>
  616. <section id="framesummary-objects">
  617. <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>
  618. <div class="versionadded">
  619. <p><span class="versionmodified added">New in version 3.5.</span></p>
  620. </div>
  621. <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>
  622. in a <a class="reference internal" href="../reference/datamodel.html#traceback-objects"><span class="std std-ref">traceback</span></a>.</p>
  623. <dl class="py class">
  624. <dt class="sig sig-object py" id="traceback.FrameSummary">
  625. <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>
  626. <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
  627. <a class="reference internal" href="../reference/datamodel.html#traceback-objects"><span class="std std-ref">traceback</span></a> or stack that is being formatted
  628. or printed. It may optionally have a stringified version of the frame’s
  629. 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
  630. 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>
  631. 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>).
  632. <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
  633. lookups happening at all. <em>locals</em> is an optional local variable
  634. dictionary, and if supplied the variable representations are stored in the
  635. summary for later display.</p>
  636. <p><code class="xref py py-class docutils literal notranslate"><span class="pre">FrameSummary</span></code> instances have the following attributes:</p>
  637. <dl class="py attribute">
  638. <dt class="sig sig-object py" id="traceback.FrameSummary.filename">
  639. <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>
  640. <dd><p>The filename of the source code for this frame. Equivalent to accessing
  641. <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
  642. <a class="reference internal" href="../reference/datamodel.html#frame-objects"><span class="std std-ref">frame object</span></a> <em>f</em>.</p>
  643. </dd></dl>
  644. <dl class="py attribute">
  645. <dt class="sig sig-object py" id="traceback.FrameSummary.lineno">
  646. <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>
  647. <dd><p>The line number of the source code for this frame.</p>
  648. </dd></dl>
  649. <dl class="py attribute">
  650. <dt class="sig sig-object py" id="traceback.FrameSummary.name">
  651. <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>
  652. <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
  653. a <a class="reference internal" href="../reference/datamodel.html#frame-objects"><span class="std std-ref">frame object</span></a> <em>f</em>.</p>
  654. </dd></dl>
  655. <dl class="py attribute">
  656. <dt class="sig sig-object py" id="traceback.FrameSummary.line">
  657. <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>
  658. <dd><p>A string representing the source code for this frame, with leading and
  659. trailing whitespace stripped.
  660. If the source is not available, it is <code class="docutils literal notranslate"><span class="pre">None</span></code>.</p>
  661. </dd></dl>
  662. </dd></dl>
  663. </section>
  664. <section id="traceback-examples">
  665. <span id="traceback-example"></span><h2>Traceback Examples<a class="headerlink" href="#traceback-examples" title="Link to this heading">¶</a></h2>
  666. <p>This simple example implements a basic read-eval-print loop, similar to (but
  667. less useful than) the standard Python interactive interpreter loop. For a more
  668. 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>
  669. module.</p>
  670. <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>
  671. <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>
  672. <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>
  673. <span class="k">try</span><span class="p">:</span>
  674. <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>
  675. <span class="k">except</span> <span class="ne">Exception</span><span class="p">:</span>
  676. <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;Exception in user code:&quot;</span><span class="p">)</span>
  677. <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>
  678. <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>
  679. <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>
  680. <span class="n">envdir</span> <span class="o">=</span> <span class="p">{}</span>
  681. <span class="k">while</span> <span class="kc">True</span><span class="p">:</span>
  682. <span class="n">run_user_code</span><span class="p">(</span><span class="n">envdir</span><span class="p">)</span>
  683. </pre></div>
  684. </div>
  685. <p>The following example demonstrates the different ways to print and format the
  686. exception and traceback:</p>
  687. <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>
  688. <span class="k">def</span> <span class="nf">lumberjack</span><span class="p">():</span>
  689. <span class="n">bright_side_of_life</span><span class="p">()</span>
  690. <span class="k">def</span> <span class="nf">bright_side_of_life</span><span class="p">():</span>
  691. <span class="k">return</span> <span class="nb">tuple</span><span class="p">()[</span><span class="mi">0</span><span class="p">]</span>
  692. <span class="k">try</span><span class="p">:</span>
  693. <span class="n">lumberjack</span><span class="p">()</span>
  694. <span class="k">except</span> <span class="ne">IndexError</span><span class="p">:</span>
  695. <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>
  696. <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;*** print_tb:&quot;</span><span class="p">)</span>
  697. <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>
  698. <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;*** print_exception:&quot;</span><span class="p">)</span>
  699. <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>
  700. <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;*** print_exc:&quot;</span><span class="p">)</span>
  701. <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>
  702. <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>
  703. <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>
  704. <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>
  705. <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>
  706. <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;*** format_exception:&quot;</span><span class="p">)</span>
  707. <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>
  708. <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;*** extract_tb:&quot;</span><span class="p">)</span>
  709. <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>
  710. <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;*** format_tb:&quot;</span><span class="p">)</span>
  711. <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>
  712. <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>
  713. </pre></div>
  714. </div>
  715. <p>The output for the example would look similar to this:</p>
  716. <div class="highlight-none notranslate"><div class="highlight"><pre><span></span>*** print_tb:
  717. File &quot;&lt;doctest...&gt;&quot;, line 10, in &lt;module&gt;
  718. lumberjack()
  719. *** print_exception:
  720. Traceback (most recent call last):
  721. File &quot;&lt;doctest...&gt;&quot;, line 10, in &lt;module&gt;
  722. lumberjack()
  723. File &quot;&lt;doctest...&gt;&quot;, line 4, in lumberjack
  724. bright_side_of_life()
  725. IndexError: tuple index out of range
  726. *** print_exc:
  727. Traceback (most recent call last):
  728. File &quot;&lt;doctest...&gt;&quot;, line 10, in &lt;module&gt;
  729. lumberjack()
  730. File &quot;&lt;doctest...&gt;&quot;, line 4, in lumberjack
  731. bright_side_of_life()
  732. IndexError: tuple index out of range
  733. *** format_exc, first and last line:
  734. Traceback (most recent call last):
  735. IndexError: tuple index out of range
  736. *** format_exception:
  737. [&#39;Traceback (most recent call last):\n&#39;,
  738. &#39; File &quot;&lt;doctest default[0]&gt;&quot;, line 10, in &lt;module&gt;\n lumberjack()\n&#39;,
  739. &#39; File &quot;&lt;doctest default[0]&gt;&quot;, line 4, in lumberjack\n bright_side_of_life()\n&#39;,
  740. &#39; File &quot;&lt;doctest default[0]&gt;&quot;, line 7, in bright_side_of_life\n return tuple()[0]\n ~~~~~~~^^^\n&#39;,
  741. &#39;IndexError: tuple index out of range\n&#39;]
  742. *** extract_tb:
  743. [&lt;FrameSummary file &lt;doctest...&gt;, line 10 in &lt;module&gt;&gt;,
  744. &lt;FrameSummary file &lt;doctest...&gt;, line 4 in lumberjack&gt;,
  745. &lt;FrameSummary file &lt;doctest...&gt;, line 7 in bright_side_of_life&gt;]
  746. *** format_tb:
  747. [&#39; File &quot;&lt;doctest default[0]&gt;&quot;, line 10, in &lt;module&gt;\n lumberjack()\n&#39;,
  748. &#39; File &quot;&lt;doctest default[0]&gt;&quot;, line 4, in lumberjack\n bright_side_of_life()\n&#39;,
  749. &#39; File &quot;&lt;doctest default[0]&gt;&quot;, line 7, in bright_side_of_life\n return tuple()[0]\n ~~~~~~~^^^\n&#39;]
  750. *** tb_lineno: 10
  751. </pre></div>
  752. </div>
  753. <p>The following example shows the different ways to print and format the stack:</p>
  754. <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>
  755. <span class="gp">&gt;&gt;&gt; </span><span class="k">def</span> <span class="nf">another_function</span><span class="p">():</span>
  756. <span class="gp">... </span> <span class="n">lumberstack</span><span class="p">()</span>
  757. <span class="gp">...</span>
  758. <span class="gp">&gt;&gt;&gt; </span><span class="k">def</span> <span class="nf">lumberstack</span><span class="p">():</span>
  759. <span class="gp">... </span> <span class="n">traceback</span><span class="o">.</span><span class="n">print_stack</span><span class="p">()</span>
  760. <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>
  761. <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>
  762. <span class="gp">...</span>
  763. <span class="gp">&gt;&gt;&gt; </span><span class="n">another_function</span><span class="p">()</span>
  764. File <span class="nb">&quot;&lt;doctest&gt;&quot;</span>, line <span class="m">10</span>, in <span class="n">&lt;module&gt;</span>
  765. <span class="w"> </span><span class="n">another_function</span><span class="p">()</span>
  766. File <span class="nb">&quot;&lt;doctest&gt;&quot;</span>, line <span class="m">3</span>, in <span class="n">another_function</span>
  767. <span class="w"> </span><span class="n">lumberstack</span><span class="p">()</span>
  768. File <span class="nb">&quot;&lt;doctest&gt;&quot;</span>, line <span class="m">6</span>, in <span class="n">lumberstack</span>
  769. <span class="w"> </span><span class="n">traceback</span><span class="o">.</span><span class="n">print_stack</span><span class="p">()</span>
  770. <span class="x">[(&#39;&lt;doctest&gt;&#39;, 10, &#39;&lt;module&gt;&#39;, &#39;another_function()&#39;),</span>
  771. <span class="x"> (&#39;&lt;doctest&gt;&#39;, 3, &#39;another_function&#39;, &#39;lumberstack()&#39;),</span>
  772. <span class="x"> (&#39;&lt;doctest&gt;&#39;, 7, &#39;lumberstack&#39;, &#39;print(repr(traceback.extract_stack()))&#39;)]</span>
  773. <span class="x">[&#39; File &quot;&lt;doctest&gt;&quot;, line 10, in &lt;module&gt;\n another_function()\n&#39;,</span>
  774. <span class="x"> &#39; File &quot;&lt;doctest&gt;&quot;, line 3, in another_function\n lumberstack()\n&#39;,</span>
  775. <span class="x"> &#39; File &quot;&lt;doctest&gt;&quot;, line 8, in lumberstack\n print(repr(traceback.format_stack()))\n&#39;]</span>
  776. </pre></div>
  777. </div>
  778. <p>This last example demonstrates the final few formatting functions:</p>
  779. <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>
  780. <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>
  781. <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>
  782. <span class="go">[&#39; File &quot;spam.py&quot;, line 3, in &lt;module&gt;\n spam.eggs()\n&#39;,</span>
  783. <span class="go"> &#39; File &quot;eggs.py&quot;, line 42, in eggs\n return &quot;bacon&quot;\n&#39;]</span>
  784. <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>
  785. <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>
  786. <span class="go">[&#39;IndexError: tuple index out of range\n&#39;]</span>
  787. </pre></div>
  788. </div>
  789. </section>
  790. </section>
  791. <div class="clearer"></div>
  792. </div>
  793. </div>
  794. </div>
  795. <div class="sphinxsidebar" role="navigation" aria-label="main navigation">
  796. <div class="sphinxsidebarwrapper">
  797. <div>
  798. <h3><a href="../contents.html">Table of Contents</a></h3>
  799. <ul>
  800. <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>
  801. <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>
  802. <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>
  803. <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>
  804. <li><a class="reference internal" href="#traceback-examples">Traceback Examples</a></li>
  805. </ul>
  806. </li>
  807. </ul>
  808. </div>
  809. <div>
  810. <h4>Previous topic</h4>
  811. <p class="topless"><a href="atexit.html"
  812. title="previous chapter"><code class="xref py py-mod docutils literal notranslate"><span class="pre">atexit</span></code> — Exit handlers</a></p>
  813. </div>
  814. <div>
  815. <h4>Next topic</h4>
  816. <p class="topless"><a href="__future__.html"
  817. title="next chapter"><code class="xref py py-mod docutils literal notranslate"><span class="pre">__future__</span></code> — Future statement definitions</a></p>
  818. </div>
  819. <div role="note" aria-label="source link">
  820. <h3>This Page</h3>
  821. <ul class="this-page-menu">
  822. <li><a href="../bugs.html">Report a Bug</a></li>
  823. <li>
  824. <a href="https://github.com/python/cpython/blob/main/Doc/library/traceback.rst"
  825. rel="nofollow">Show Source
  826. </a>
  827. </li>
  828. </ul>
  829. </div>
  830. </div>
  831. <div id="sidebarbutton" title="Collapse sidebar">
  832. <span>«</span>
  833. </div>
  834. </div>
  835. <div class="clearer"></div>
  836. </div>
  837. <div class="related" role="navigation" aria-label="related navigation">
  838. <h3>Navigation</h3>
  839. <ul>
  840. <li class="right" style="margin-right: 10px">
  841. <a href="../genindex.html" title="General Index"
  842. >index</a></li>
  843. <li class="right" >
  844. <a href="../py-modindex.html" title="Python Module Index"
  845. >modules</a> |</li>
  846. <li class="right" >
  847. <a href="__future__.html" title="__future__ — Future statement definitions"
  848. >next</a> |</li>
  849. <li class="right" >
  850. <a href="atexit.html" title="atexit — Exit handlers"
  851. >previous</a> |</li>
  852. <li><img src="../_static/py.svg" alt="Python logo" style="vertical-align: middle; margin-top: -1px"/></li>
  853. <li><a href="https://www.python.org/">Python</a> &#187;</li>
  854. <li class="switchers">
  855. <div class="language_switcher_placeholder"></div>
  856. <div class="version_switcher_placeholder"></div>
  857. </li>
  858. <li>
  859. </li>
  860. <li id="cpython-language-and-version">
  861. <a href="../index.html">3.12.3 Documentation</a> &#187;
  862. </li>
  863. <li class="nav-item nav-item-1"><a href="index.html" >The Python Standard Library</a> &#187;</li>
  864. <li class="nav-item nav-item-2"><a href="python.html" >Python Runtime Services</a> &#187;</li>
  865. <li class="nav-item nav-item-this"><a href=""><code class="xref py py-mod docutils literal notranslate"><span class="pre">traceback</span></code> — Print or retrieve a stack traceback</a></li>
  866. <li class="right">
  867. <div class="inline-search" role="search">
  868. <form class="inline-search" action="../search.html" method="get">
  869. <input placeholder="Quick search" aria-label="Quick search" type="search" name="q" id="search-box" />
  870. <input type="submit" value="Go" />
  871. </form>
  872. </div>
  873. |
  874. </li>
  875. <li class="right">
  876. <label class="theme-selector-label">
  877. Theme
  878. <select class="theme-selector" oninput="activateTheme(this.value)">
  879. <option value="auto" selected>Auto</option>
  880. <option value="light">Light</option>
  881. <option value="dark">Dark</option>
  882. </select>
  883. </label> |</li>
  884. </ul>
  885. </div>
  886. <div class="footer">
  887. &copy;
  888. <a href="../copyright.html">
  889. Copyright
  890. </a>
  891. 2001-2024, Python Software Foundation.
  892. <br />
  893. This page is licensed under the Python Software Foundation License Version 2.
  894. <br />
  895. Examples, recipes, and other code in the documentation are additionally licensed under the Zero Clause BSD License.
  896. <br />
  897. See <a href="/license.html">History and License</a> for more information.<br />
  898. <br />
  899. The Python Software Foundation is a non-profit corporation.
  900. <a href="https://www.python.org/psf/donations/">Please donate.</a>
  901. <br />
  902. <br />
  903. Last updated on Apr 09, 2024 (13:47 UTC).
  904. <a href="/bugs.html">Found a bug</a>?
  905. <br />
  906. Created using <a href="https://www.sphinx-doc.org/">Sphinx</a> 7.2.6.
  907. </div>
  908. </body>
  909. </html>
上海开阖软件有限公司 沪ICP备12045867号-1