Edit File: inspect.html
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>27.13. inspect — Inspect live objects — Python 2.7.5 documentation</title> <link rel="stylesheet" href="../_static/default.css" type="text/css" /> <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> <script type="text/javascript"> var DOCUMENTATION_OPTIONS = { URL_ROOT: '../', VERSION: '2.7.5', COLLAPSE_INDEX: false, FILE_SUFFIX: '.html', HAS_SOURCE: true }; </script> <script type="text/javascript" src="../_static/jquery.js"></script> <script type="text/javascript" src="../_static/underscore.js"></script> <script type="text/javascript" src="../_static/doctools.js"></script> <script type="text/javascript" src="../_static/sidebar.js"></script> <link rel="search" type="application/opensearchdescription+xml" title="Search within Python 2.7.5 documentation" href="../_static/opensearch.xml"/> <link rel="author" title="About these documents" href="../about.html" /> <link rel="copyright" title="Copyright" href="../copyright.html" /> <link rel="top" title="Python 2.7.5 documentation" href="../index.html" /> <link rel="up" title="27. 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Python Runtime Services</a> »</li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body"> <div class="section" id="module-inspect"> <span id="inspect-inspect-live-objects"></span><h1>27.13. <a class="reference internal" href="#module-inspect" title="inspect: Extract information and source code from live objects."><tt class="xref py py-mod docutils literal"><span class="pre">inspect</span></tt></a> — Inspect live objects<a class="headerlink" href="#module-inspect" title="Permalink to this headline">¶</a></h1> <p class="versionadded"> <span class="versionmodified">New in version 2.1.</span></p> <p><strong>Source code:</strong> <a class="reference external" href="http://hg.python.org/cpython/file/2.7/Lib/inspect.py">Lib/inspect.py</a></p> <hr class="docutils" /> <p>The <a class="reference internal" href="#module-inspect" title="inspect: Extract information and source code from live objects."><tt class="xref py py-mod docutils literal"><span class="pre">inspect</span></tt></a> module provides several useful functions to help get information about live objects such as modules, classes, methods, functions, tracebacks, frame objects, and code objects. For example, it can help you examine the contents of a class, retrieve the source code of a method, extract and format the argument list for a function, or get all the information you need to display a detailed traceback.</p> <p>There are four main kinds of services provided by this module: type checking, getting source code, inspecting classes and functions, and examining the interpreter stack.</p> <div class="section" id="types-and-members"> <span id="inspect-types"></span><h2>27.13.1. Types and members<a class="headerlink" href="#types-and-members" title="Permalink to this headline">¶</a></h2> <p>The <a class="reference internal" href="#inspect.getmembers" title="inspect.getmembers"><tt class="xref py py-func docutils literal"><span class="pre">getmembers()</span></tt></a> function retrieves the members of an object such as a class or module. The sixteen functions whose names begin with “is” are mainly provided as convenient choices for the second argument to <a class="reference internal" href="#inspect.getmembers" title="inspect.getmembers"><tt class="xref py py-func docutils literal"><span class="pre">getmembers()</span></tt></a>. They also help you determine when you can expect to find the following special attributes:</p> <table border="1" class="docutils"> <colgroup> <col width="18%" /> <col width="27%" /> <col width="44%" /> <col width="11%" /> </colgroup> <thead valign="bottom"> <tr class="row-odd"><th class="head">Type</th> <th class="head">Attribute</th> <th class="head">Description</th> <th class="head">Notes</th> </tr> </thead> <tbody valign="top"> <tr class="row-even"><td>module</td> <td>__doc__</td> <td>documentation string</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>__file__</td> <td>filename (missing for built-in modules)</td> <td> </td> </tr> <tr class="row-even"><td>class</td> <td>__doc__</td> <td>documentation string</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>__module__</td> <td>name of module in which this class was defined</td> <td> </td> </tr> <tr class="row-even"><td>method</td> <td>__doc__</td> <td>documentation string</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>__name__</td> <td>name with which this method was defined</td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>im_class</td> <td>class object that asked for this method</td> <td>(1)</td> </tr> <tr class="row-odd"><td> </td> <td>im_func or __func__</td> <td>function object containing implementation of method</td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>im_self or __self__</td> <td>instance to which this method is bound, or <tt class="docutils literal"><span class="pre">None</span></tt></td> <td> </td> </tr> <tr class="row-odd"><td>function</td> <td>__doc__</td> <td>documentation string</td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>__name__</td> <td>name with which this function was defined</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>func_code</td> <td>code object containing compiled function <a class="reference internal" href="../glossary.html#term-bytecode"><em class="xref std std-term">bytecode</em></a></td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>func_defaults</td> <td>tuple of any default values for arguments</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>func_doc</td> <td>(same as __doc__)</td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>func_globals</td> <td>global namespace in which this function was defined</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>func_name</td> <td>(same as __name__)</td> <td> </td> </tr> <tr class="row-even"><td>generator</td> <td>__iter__</td> <td>defined to support iteration over container</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>close</td> <td>raises new GeneratorExit exception inside the generator to terminate the iteration</td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>gi_code</td> <td>code object</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>gi_frame</td> <td>frame object or possibly None once the generator has been exhausted</td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>gi_running</td> <td>set to 1 when generator is executing, 0 otherwise</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>next</td> <td>return the next item from the container</td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>send</td> <td>resumes the generator and “sends” a value that becomes the result of the current yield-expression</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>throw</td> <td>used to raise an exception inside the generator</td> <td> </td> </tr> <tr class="row-even"><td>traceback</td> <td>tb_frame</td> <td>frame object at this level</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>tb_lasti</td> <td>index of last attempted instruction in bytecode</td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>tb_lineno</td> <td>current line number in Python source code</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>tb_next</td> <td>next inner traceback object (called by this level)</td> <td> </td> </tr> <tr class="row-even"><td>frame</td> <td>f_back</td> <td>next outer frame object (this frame’s caller)</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>f_builtins</td> <td>builtins namespace seen by this frame</td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>f_code</td> <td>code object being executed in this frame</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>f_exc_traceback</td> <td>traceback if raised in this frame, or <tt class="docutils literal"><span class="pre">None</span></tt></td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>f_exc_type</td> <td>exception type if raised in this frame, or <tt class="docutils literal"><span class="pre">None</span></tt></td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>f_exc_value</td> <td>exception value if raised in this frame, or <tt class="docutils literal"><span class="pre">None</span></tt></td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>f_globals</td> <td>global namespace seen by this frame</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>f_lasti</td> <td>index of last attempted instruction in bytecode</td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>f_lineno</td> <td>current line number in Python source code</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>f_locals</td> <td>local namespace seen by this frame</td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>f_restricted</td> <td>0 or 1 if frame is in restricted execution mode</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>f_trace</td> <td>tracing function for this frame, or <tt class="docutils literal"><span class="pre">None</span></tt></td> <td> </td> </tr> <tr class="row-even"><td>code</td> <td>co_argcount</td> <td>number of arguments (not including * or ** args)</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>co_code</td> <td>string of raw compiled bytecode</td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>co_consts</td> <td>tuple of constants used in the bytecode</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>co_filename</td> <td>name of file in which this code object was created</td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>co_firstlineno</td> <td>number of first line in Python source code</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>co_flags</td> <td>bitmap: 1=optimized <tt class="docutils literal"><span class="pre">|</span></tt> 2=newlocals <tt class="docutils literal"><span class="pre">|</span></tt> 4=*arg <tt class="docutils literal"><span class="pre">|</span></tt> 8=**arg</td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>co_lnotab</td> <td>encoded mapping of line numbers to bytecode indices</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>co_name</td> <td>name with which this code object was defined</td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>co_names</td> <td>tuple of names of local variables</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>co_nlocals</td> <td>number of local variables</td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>co_stacksize</td> <td>virtual machine stack space required</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>co_varnames</td> <td>tuple of names of arguments and local variables</td> <td> </td> </tr> <tr class="row-even"><td>builtin</td> <td>__doc__</td> <td>documentation string</td> <td> </td> </tr> <tr class="row-odd"><td> </td> <td>__name__</td> <td>original name of this function or method</td> <td> </td> </tr> <tr class="row-even"><td> </td> <td>__self__</td> <td>instance to which a method is bound, or <tt class="docutils literal"><span class="pre">None</span></tt></td> <td> </td> </tr> </tbody> </table> <p>Note:</p> <ol class="arabic"> <li><p class="first versionchanged"> <span class="versionmodified">Changed in version 2.2: </span><tt class="xref py py-attr docutils literal"><span class="pre">im_class</span></tt> used to refer to the class that defined the method.</p> </li> </ol> <dl class="function"> <dt id="inspect.getmembers"> <tt class="descclassname">inspect.</tt><tt class="descname">getmembers</tt><big>(</big><em>object</em><span class="optional">[</span>, <em>predicate</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#inspect.getmembers" title="Permalink to this definition">¶</a></dt> <dd><p>Return all the members of an object in a list of (name, value) pairs sorted by name. If the optional <em>predicate</em> argument is supplied, only members for which the predicate returns a true value are included.</p> <div class="admonition note"> <p class="first admonition-title">Note</p> <p class="last"><a class="reference internal" href="#inspect.getmembers" title="inspect.getmembers"><tt class="xref py py-func docutils literal"><span class="pre">getmembers()</span></tt></a> does not return metaclass attributes when the argument is a class (this behavior is inherited from the <a class="reference internal" href="functions.html#dir" title="dir"><tt class="xref py py-func docutils literal"><span class="pre">dir()</span></tt></a> function).</p> </div> </dd></dl> <dl class="function"> <dt id="inspect.getmoduleinfo"> <tt class="descclassname">inspect.</tt><tt class="descname">getmoduleinfo</tt><big>(</big><em>path</em><big>)</big><a class="headerlink" href="#inspect.getmoduleinfo" title="Permalink to this definition">¶</a></dt> <dd><p>Return a tuple of values that describe how Python will interpret the file identified by <em>path</em> if it is a module, or <tt class="docutils literal"><span class="pre">None</span></tt> if it would not be identified as a module. The return tuple is <tt class="docutils literal"><span class="pre">(name,</span> <span class="pre">suffix,</span> <span class="pre">mode,</span> <span class="pre">module_type)</span></tt>, where <em>name</em> is the name of the module without the name of any enclosing package, <em>suffix</em> is the trailing part of the file name (which may not be a dot-delimited extension), <em>mode</em> is the <a class="reference internal" href="functions.html#open" title="open"><tt class="xref py py-func docutils literal"><span class="pre">open()</span></tt></a> mode that would be used (<tt class="docutils literal"><span class="pre">'r'</span></tt> or <tt class="docutils literal"><span class="pre">'rb'</span></tt>), and <em>module_type</em> is an integer giving the type of the module. <em>module_type</em> will have a value which can be compared to the constants defined in the <a class="reference internal" href="imp.html#module-imp" title="imp: Access the implementation of the import statement."><tt class="xref py py-mod docutils literal"><span class="pre">imp</span></tt></a> module; see the documentation for that module for more information on module types.</p> <p class="versionchanged"> <span class="versionmodified">Changed in version 2.6: </span>Returns a <a class="reference internal" href="../glossary.html#term-named-tuple"><em class="xref std std-term">named tuple</em></a> <tt class="docutils literal"><span class="pre">ModuleInfo(name,</span> <span class="pre">suffix,</span> <span class="pre">mode,</span> <span class="pre">module_type)</span></tt>.</p> </dd></dl> <dl class="function"> <dt id="inspect.getmodulename"> <tt class="descclassname">inspect.</tt><tt class="descname">getmodulename</tt><big>(</big><em>path</em><big>)</big><a class="headerlink" href="#inspect.getmodulename" title="Permalink to this definition">¶</a></dt> <dd><p>Return the name of the module named by the file <em>path</em>, without including the names of enclosing packages. This uses the same algorithm as the interpreter uses when searching for modules. If the name cannot be matched according to the interpreter’s rules, <tt class="docutils literal"><span class="pre">None</span></tt> is returned.</p> </dd></dl> <dl class="function"> <dt id="inspect.ismodule"> <tt class="descclassname">inspect.</tt><tt class="descname">ismodule</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.ismodule" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if the object is a module.</p> </dd></dl> <dl class="function"> <dt id="inspect.isclass"> <tt class="descclassname">inspect.</tt><tt class="descname">isclass</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.isclass" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if the object is a class, whether built-in or created in Python code.</p> </dd></dl> <dl class="function"> <dt id="inspect.ismethod"> <tt class="descclassname">inspect.</tt><tt class="descname">ismethod</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.ismethod" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if the object is a bound method written in Python.</p> </dd></dl> <dl class="function"> <dt id="inspect.isfunction"> <tt class="descclassname">inspect.</tt><tt class="descname">isfunction</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.isfunction" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if the object is a Python function, which includes functions created by a <a class="reference internal" href="../glossary.html#term-lambda"><em class="xref std std-term">lambda</em></a> expression.</p> </dd></dl> <dl class="function"> <dt id="inspect.isgeneratorfunction"> <tt class="descclassname">inspect.</tt><tt class="descname">isgeneratorfunction</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.isgeneratorfunction" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if the object is a Python generator function.</p> <p class="versionadded"> <span class="versionmodified">New in version 2.6.</span></p> </dd></dl> <dl class="function"> <dt id="inspect.isgenerator"> <tt class="descclassname">inspect.</tt><tt class="descname">isgenerator</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.isgenerator" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if the object is a generator.</p> <p class="versionadded"> <span class="versionmodified">New in version 2.6.</span></p> </dd></dl> <dl class="function"> <dt id="inspect.istraceback"> <tt class="descclassname">inspect.</tt><tt class="descname">istraceback</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.istraceback" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if the object is a traceback.</p> </dd></dl> <dl class="function"> <dt id="inspect.isframe"> <tt class="descclassname">inspect.</tt><tt class="descname">isframe</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.isframe" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if the object is a frame.</p> </dd></dl> <dl class="function"> <dt id="inspect.iscode"> <tt class="descclassname">inspect.</tt><tt class="descname">iscode</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.iscode" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if the object is a code.</p> </dd></dl> <dl class="function"> <dt id="inspect.isbuiltin"> <tt class="descclassname">inspect.</tt><tt class="descname">isbuiltin</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.isbuiltin" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if the object is a built-in function or a bound built-in method.</p> </dd></dl> <dl class="function"> <dt id="inspect.isroutine"> <tt class="descclassname">inspect.</tt><tt class="descname">isroutine</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.isroutine" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if the object is a user-defined or built-in function or method.</p> </dd></dl> <dl class="function"> <dt id="inspect.isabstract"> <tt class="descclassname">inspect.</tt><tt class="descname">isabstract</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.isabstract" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if the object is an abstract base class.</p> <p class="versionadded"> <span class="versionmodified">New in version 2.6.</span></p> </dd></dl> <dl class="function"> <dt id="inspect.ismethoddescriptor"> <tt class="descclassname">inspect.</tt><tt class="descname">ismethoddescriptor</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.ismethoddescriptor" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if the object is a method descriptor, but not if <a class="reference internal" href="#inspect.ismethod" title="inspect.ismethod"><tt class="xref py py-func docutils literal"><span class="pre">ismethod()</span></tt></a>, <a class="reference internal" href="#inspect.isclass" title="inspect.isclass"><tt class="xref py py-func docutils literal"><span class="pre">isclass()</span></tt></a>, <a class="reference internal" href="#inspect.isfunction" title="inspect.isfunction"><tt class="xref py py-func docutils literal"><span class="pre">isfunction()</span></tt></a> or <a class="reference internal" href="#inspect.isbuiltin" title="inspect.isbuiltin"><tt class="xref py py-func docutils literal"><span class="pre">isbuiltin()</span></tt></a> are true.</p> <p>This is new as of Python 2.2, and, for example, is true of <tt class="docutils literal"><span class="pre">int.__add__</span></tt>. An object passing this test has a <tt class="xref py py-attr docutils literal"><span class="pre">__get__</span></tt> attribute but not a <tt class="xref py py-attr docutils literal"><span class="pre">__set__</span></tt> attribute, but beyond that the set of attributes varies. <tt class="xref py py-attr docutils literal"><span class="pre">__name__</span></tt> is usually sensible, and <tt class="xref py py-attr docutils literal"><span class="pre">__doc__</span></tt> often is.</p> <p>Methods implemented via descriptors that also pass one of the other tests return false from the <a class="reference internal" href="#inspect.ismethoddescriptor" title="inspect.ismethoddescriptor"><tt class="xref py py-func docutils literal"><span class="pre">ismethoddescriptor()</span></tt></a> test, simply because the other tests promise more – you can, e.g., count on having the <tt class="xref py py-attr docutils literal"><span class="pre">im_func</span></tt> attribute (etc) when an object passes <a class="reference internal" href="#inspect.ismethod" title="inspect.ismethod"><tt class="xref py py-func docutils literal"><span class="pre">ismethod()</span></tt></a>.</p> </dd></dl> <dl class="function"> <dt id="inspect.isdatadescriptor"> <tt class="descclassname">inspect.</tt><tt class="descname">isdatadescriptor</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.isdatadescriptor" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if the object is a data descriptor.</p> <p>Data descriptors have both a <tt class="xref py py-attr docutils literal"><span class="pre">__get__</span></tt> and a <tt class="xref py py-attr docutils literal"><span class="pre">__set__</span></tt> attribute. Examples are properties (defined in Python), getsets, and members. The latter two are defined in C and there are more specific tests available for those types, which is robust across Python implementations. Typically, data descriptors will also have <tt class="xref py py-attr docutils literal"><span class="pre">__name__</span></tt> and <tt class="xref py py-attr docutils literal"><span class="pre">__doc__</span></tt> attributes (properties, getsets, and members have both of these attributes), but this is not guaranteed.</p> <p class="versionadded"> <span class="versionmodified">New in version 2.3.</span></p> </dd></dl> <dl class="function"> <dt id="inspect.isgetsetdescriptor"> <tt class="descclassname">inspect.</tt><tt class="descname">isgetsetdescriptor</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.isgetsetdescriptor" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if the object is a getset descriptor.</p> <div class="impl-detail compound"> <p><strong>CPython implementation detail:</strong> getsets are attributes defined in extension modules via <tt class="xref c c-type docutils literal"><span class="pre">PyGetSetDef</span></tt> structures. For Python implementations without such types, this method will always return <tt class="docutils literal"><span class="pre">False</span></tt>.</p> </div> <p class="versionadded"> <span class="versionmodified">New in version 2.5.</span></p> </dd></dl> <dl class="function"> <dt id="inspect.ismemberdescriptor"> <tt class="descclassname">inspect.</tt><tt class="descname">ismemberdescriptor</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.ismemberdescriptor" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if the object is a member descriptor.</p> <div class="impl-detail compound"> <p><strong>CPython implementation detail:</strong> Member descriptors are attributes defined in extension modules via <a class="reference internal" href="../c-api/structures.html#PyMemberDef" title="PyMemberDef"><tt class="xref c c-type docutils literal"><span class="pre">PyMemberDef</span></tt></a> structures. For Python implementations without such types, this method will always return <tt class="docutils literal"><span class="pre">False</span></tt>.</p> </div> <p class="versionadded"> <span class="versionmodified">New in version 2.5.</span></p> </dd></dl> </div> <div class="section" id="retrieving-source-code"> <span id="inspect-source"></span><h2>27.13.2. Retrieving source code<a class="headerlink" href="#retrieving-source-code" title="Permalink to this headline">¶</a></h2> <dl class="function"> <dt id="inspect.getdoc"> <tt class="descclassname">inspect.</tt><tt class="descname">getdoc</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.getdoc" title="Permalink to this definition">¶</a></dt> <dd><p>Get the documentation string for an object, cleaned up with <a class="reference internal" href="#inspect.cleandoc" title="inspect.cleandoc"><tt class="xref py py-func docutils literal"><span class="pre">cleandoc()</span></tt></a>.</p> </dd></dl> <dl class="function"> <dt id="inspect.getcomments"> <tt class="descclassname">inspect.</tt><tt class="descname">getcomments</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.getcomments" title="Permalink to this definition">¶</a></dt> <dd><p>Return in a single string any lines of comments immediately preceding the object’s source code (for a class, function, or method), or at the top of the Python source file (if the object is a module).</p> </dd></dl> <dl class="function"> <dt id="inspect.getfile"> <tt class="descclassname">inspect.</tt><tt class="descname">getfile</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.getfile" title="Permalink to this definition">¶</a></dt> <dd><p>Return the name of the (text or binary) file in which an object was defined. This will fail with a <a class="reference internal" href="exceptions.html#exceptions.TypeError" title="exceptions.TypeError"><tt class="xref py py-exc docutils literal"><span class="pre">TypeError</span></tt></a> if the object is a built-in module, class, or function.</p> </dd></dl> <dl class="function"> <dt id="inspect.getmodule"> <tt class="descclassname">inspect.</tt><tt class="descname">getmodule</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.getmodule" title="Permalink to this definition">¶</a></dt> <dd><p>Try to guess which module an object was defined in.</p> </dd></dl> <dl class="function"> <dt id="inspect.getsourcefile"> <tt class="descclassname">inspect.</tt><tt class="descname">getsourcefile</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.getsourcefile" title="Permalink to this definition">¶</a></dt> <dd><p>Return the name of the Python source file in which an object was defined. This will fail with a <a class="reference internal" href="exceptions.html#exceptions.TypeError" title="exceptions.TypeError"><tt class="xref py py-exc docutils literal"><span class="pre">TypeError</span></tt></a> if the object is a built-in module, class, or function.</p> </dd></dl> <dl class="function"> <dt id="inspect.getsourcelines"> <tt class="descclassname">inspect.</tt><tt class="descname">getsourcelines</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.getsourcelines" title="Permalink to this definition">¶</a></dt> <dd><p>Return a list of source lines and starting line number for an object. The argument may be a module, class, method, function, traceback, frame, or code object. The source code is returned as a list of the lines corresponding to the object and the line number indicates where in the original source file the first line of code was found. An <a class="reference internal" href="exceptions.html#exceptions.IOError" title="exceptions.IOError"><tt class="xref py py-exc docutils literal"><span class="pre">IOError</span></tt></a> is raised if the source code cannot be retrieved.</p> </dd></dl> <dl class="function"> <dt id="inspect.getsource"> <tt class="descclassname">inspect.</tt><tt class="descname">getsource</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#inspect.getsource" title="Permalink to this definition">¶</a></dt> <dd><p>Return the text of the source code for an object. The argument may be a module, class, method, function, traceback, frame, or code object. The source code is returned as a single string. An <a class="reference internal" href="exceptions.html#exceptions.IOError" title="exceptions.IOError"><tt class="xref py py-exc docutils literal"><span class="pre">IOError</span></tt></a> is raised if the source code cannot be retrieved.</p> </dd></dl> <dl class="function"> <dt id="inspect.cleandoc"> <tt class="descclassname">inspect.</tt><tt class="descname">cleandoc</tt><big>(</big><em>doc</em><big>)</big><a class="headerlink" href="#inspect.cleandoc" title="Permalink to this definition">¶</a></dt> <dd><p>Clean up indentation from docstrings that are indented to line up with blocks of code. Any whitespace that can be uniformly removed from the second line onwards is removed. Also, all tabs are expanded to spaces.</p> <p class="versionadded"> <span class="versionmodified">New in version 2.6.</span></p> </dd></dl> </div> <div class="section" id="classes-and-functions"> <span id="inspect-classes-functions"></span><h2>27.13.3. Classes and functions<a class="headerlink" href="#classes-and-functions" title="Permalink to this headline">¶</a></h2> <dl class="function"> <dt id="inspect.getclasstree"> <tt class="descclassname">inspect.</tt><tt class="descname">getclasstree</tt><big>(</big><em>classes</em><span class="optional">[</span>, <em>unique</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#inspect.getclasstree" title="Permalink to this definition">¶</a></dt> <dd><p>Arrange the given list of classes into a hierarchy of nested lists. Where a nested list appears, it contains classes derived from the class whose entry immediately precedes the list. Each entry is a 2-tuple containing a class and a tuple of its base classes. If the <em>unique</em> argument is true, exactly one entry appears in the returned structure for each class in the given list. Otherwise, classes using multiple inheritance and their descendants will appear multiple times.</p> </dd></dl> <dl class="function"> <dt id="inspect.getargspec"> <tt class="descclassname">inspect.</tt><tt class="descname">getargspec</tt><big>(</big><em>func</em><big>)</big><a class="headerlink" href="#inspect.getargspec" title="Permalink to this definition">¶</a></dt> <dd><p>Get the names and default values of a Python function’s arguments. A tuple of four things is returned: <tt class="docutils literal"><span class="pre">(args,</span> <span class="pre">varargs,</span> <span class="pre">keywords,</span> <span class="pre">defaults)</span></tt>. <em>args</em> is a list of the argument names (it may contain nested lists). <em>varargs</em> and <em>keywords</em> are the names of the <tt class="docutils literal"><span class="pre">*</span></tt> and <tt class="docutils literal"><span class="pre">**</span></tt> arguments or <tt class="docutils literal"><span class="pre">None</span></tt>. <em>defaults</em> is a tuple of default argument values or None if there are no default arguments; if this tuple has <em>n</em> elements, they correspond to the last <em>n</em> elements listed in <em>args</em>.</p> <p class="versionchanged"> <span class="versionmodified">Changed in version 2.6: </span>Returns a <a class="reference internal" href="../glossary.html#term-named-tuple"><em class="xref std std-term">named tuple</em></a> <tt class="docutils literal"><span class="pre">ArgSpec(args,</span> <span class="pre">varargs,</span> <span class="pre">keywords,</span> <span class="pre">defaults)</span></tt>.</p> </dd></dl> <dl class="function"> <dt id="inspect.getargvalues"> <tt class="descclassname">inspect.</tt><tt class="descname">getargvalues</tt><big>(</big><em>frame</em><big>)</big><a class="headerlink" href="#inspect.getargvalues" title="Permalink to this definition">¶</a></dt> <dd><p>Get information about arguments passed into a particular frame. A tuple of four things is returned: <tt class="docutils literal"><span class="pre">(args,</span> <span class="pre">varargs,</span> <span class="pre">keywords,</span> <span class="pre">locals)</span></tt>. <em>args</em> is a list of the argument names (it may contain nested lists). <em>varargs</em> and <em>keywords</em> are the names of the <tt class="docutils literal"><span class="pre">*</span></tt> and <tt class="docutils literal"><span class="pre">**</span></tt> arguments or <tt class="docutils literal"><span class="pre">None</span></tt>. <em>locals</em> is the locals dictionary of the given frame.</p> <p class="versionchanged"> <span class="versionmodified">Changed in version 2.6: </span>Returns a <a class="reference internal" href="../glossary.html#term-named-tuple"><em class="xref std std-term">named tuple</em></a> <tt class="docutils literal"><span class="pre">ArgInfo(args,</span> <span class="pre">varargs,</span> <span class="pre">keywords,</span> <span class="pre">locals)</span></tt>.</p> </dd></dl> <dl class="function"> <dt id="inspect.formatargspec"> <tt class="descclassname">inspect.</tt><tt class="descname">formatargspec</tt><big>(</big><em>args</em><span class="optional">[</span>, <em>varargs</em>, <em>varkw</em>, <em>defaults</em>, <em>formatarg</em>, <em>formatvarargs</em>, <em>formatvarkw</em>, <em>formatvalue</em>, <em>join</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#inspect.formatargspec" title="Permalink to this definition">¶</a></dt> <dd><p>Format a pretty argument spec from the four values returned by <a class="reference internal" href="#inspect.getargspec" title="inspect.getargspec"><tt class="xref py py-func docutils literal"><span class="pre">getargspec()</span></tt></a>. The format* arguments are the corresponding optional formatting functions that are called to turn names and values into strings.</p> </dd></dl> <dl class="function"> <dt id="inspect.formatargvalues"> <tt class="descclassname">inspect.</tt><tt class="descname">formatargvalues</tt><big>(</big><em>args</em><span class="optional">[</span>, <em>varargs</em>, <em>varkw</em>, <em>locals</em>, <em>formatarg</em>, <em>formatvarargs</em>, <em>formatvarkw</em>, <em>formatvalue</em>, <em>join</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#inspect.formatargvalues" title="Permalink to this definition">¶</a></dt> <dd><p>Format a pretty argument spec from the four values returned by <a class="reference internal" href="#inspect.getargvalues" title="inspect.getargvalues"><tt class="xref py py-func docutils literal"><span class="pre">getargvalues()</span></tt></a>. The format* arguments are the corresponding optional formatting functions that are called to turn names and values into strings.</p> </dd></dl> <dl class="function"> <dt id="inspect.getmro"> <tt class="descclassname">inspect.</tt><tt class="descname">getmro</tt><big>(</big><em>cls</em><big>)</big><a class="headerlink" href="#inspect.getmro" title="Permalink to this definition">¶</a></dt> <dd><p>Return a tuple of class cls’s base classes, including cls, in method resolution order. No class appears more than once in this tuple. Note that the method resolution order depends on cls’s type. Unless a very peculiar user-defined metatype is in use, cls will be the first element of the tuple.</p> </dd></dl> <dl class="function"> <dt id="inspect.getcallargs"> <tt class="descclassname">inspect.</tt><tt class="descname">getcallargs</tt><big>(</big><em>func[, *args][, **kwds]</em><big>)</big><a class="headerlink" href="#inspect.getcallargs" title="Permalink to this definition">¶</a></dt> <dd><p>Bind the <em>args</em> and <em>kwds</em> to the argument names of the Python function or method <em>func</em>, as if it was called with them. For bound methods, bind also the first argument (typically named <tt class="docutils literal"><span class="pre">self</span></tt>) to the associated instance. A dict is returned, mapping the argument names (including the names of the <tt class="docutils literal"><span class="pre">*</span></tt> and <tt class="docutils literal"><span class="pre">**</span></tt> arguments, if any) to their values from <em>args</em> and <em>kwds</em>. In case of invoking <em>func</em> incorrectly, i.e. whenever <tt class="docutils literal"><span class="pre">func(*args,</span> <span class="pre">**kwds)</span></tt> would raise an exception because of incompatible signature, an exception of the same type and the same or similar message is raised. For example:</p> <div class="highlight-python"><div class="highlight"><pre><span class="gp">>>> </span><span class="kn">from</span> <span class="nn">inspect</span> <span class="kn">import</span> <span class="n">getcallargs</span> <span class="gp">>>> </span><span class="k">def</span> <span class="nf">f</span><span class="p">(</span><span class="n">a</span><span class="p">,</span> <span class="n">b</span><span class="o">=</span><span class="mi">1</span><span class="p">,</span> <span class="o">*</span><span class="n">pos</span><span class="p">,</span> <span class="o">**</span><span class="n">named</span><span class="p">):</span> <span class="gp">... </span> <span class="k">pass</span> <span class="gp">>>> </span><span class="n">getcallargs</span><span class="p">(</span><span class="n">f</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">2</span><span class="p">,</span> <span class="mi">3</span><span class="p">)</span> <span class="go">{'a': 1, 'named': {}, 'b': 2, 'pos': (3,)}</span> <span class="gp">>>> </span><span class="n">getcallargs</span><span class="p">(</span><span class="n">f</span><span class="p">,</span> <span class="n">a</span><span class="o">=</span><span class="mi">2</span><span class="p">,</span> <span class="n">x</span><span class="o">=</span><span class="mi">4</span><span class="p">)</span> <span class="go">{'a': 2, 'named': {'x': 4}, 'b': 1, 'pos': ()}</span> <span class="gp">>>> </span><span class="n">getcallargs</span><span class="p">(</span><span class="n">f</span><span class="p">)</span> <span class="gt">Traceback (most recent call last):</span> <span class="c">...</span> <span class="gr">TypeError</span>: <span class="n">f() takes at least 1 argument (0 given)</span> </pre></div> </div> <p class="versionadded"> <span class="versionmodified">New in version 2.7.</span></p> </dd></dl> </div> <div class="section" id="the-interpreter-stack"> <span id="inspect-stack"></span><h2>27.13.4. The interpreter stack<a class="headerlink" href="#the-interpreter-stack" title="Permalink to this headline">¶</a></h2> <p>When the following functions return “frame records,” each record is a tuple of six items: the frame object, the filename, the line number of the current line, the function name, a list of lines of context from the source code, and the index of the current line within that list.</p> <div class="admonition note"> <p class="first admonition-title">Note</p> <p>Keeping references to frame objects, as found in the first element of the frame records these functions return, can cause your program to create reference cycles. Once a reference cycle has been created, the lifespan of all objects which can be accessed from the objects which form the cycle can become much longer even if Python’s optional cycle detector is enabled. If such cycles must be created, it is important to ensure they are explicitly broken to avoid the delayed destruction of objects and increased memory consumption which occurs.</p> <p>Though the cycle detector will catch these, destruction of the frames (and local variables) can be made deterministic by removing the cycle in a <a class="reference internal" href="../reference/compound_stmts.html#finally"><tt class="xref std std-keyword docutils literal"><span class="pre">finally</span></tt></a> clause. This is also important if the cycle detector was disabled when Python was compiled or using <a class="reference internal" href="gc.html#gc.disable" title="gc.disable"><tt class="xref py py-func docutils literal"><span class="pre">gc.disable()</span></tt></a>. For example:</p> <div class="last highlight-python"><pre>def handle_stackframe_without_leak(): frame = inspect.currentframe() try: # do something with the frame finally: del frame</pre> </div> </div> <p>The optional <em>context</em> argument supported by most of these functions specifies the number of lines of context to return, which are centered around the current line.</p> <dl class="function"> <dt id="inspect.getframeinfo"> <tt class="descclassname">inspect.</tt><tt class="descname">getframeinfo</tt><big>(</big><em>frame</em><span class="optional">[</span>, <em>context</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#inspect.getframeinfo" title="Permalink to this definition">¶</a></dt> <dd><p>Get information about a frame or traceback object. A 5-tuple is returned, the last five elements of the frame’s frame record.</p> <p class="versionchanged"> <span class="versionmodified">Changed in version 2.6: </span>Returns a <a class="reference internal" href="../glossary.html#term-named-tuple"><em class="xref std std-term">named tuple</em></a> <tt class="docutils literal"><span class="pre">Traceback(filename,</span> <span class="pre">lineno,</span> <span class="pre">function,</span> <span class="pre">code_context,</span> <span class="pre">index)</span></tt>.</p> </dd></dl> <dl class="function"> <dt id="inspect.getouterframes"> <tt class="descclassname">inspect.</tt><tt class="descname">getouterframes</tt><big>(</big><em>frame</em><span class="optional">[</span>, <em>context</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#inspect.getouterframes" title="Permalink to this definition">¶</a></dt> <dd><p>Get a list of frame records for a frame and all outer frames. These frames represent the calls that lead to the creation of <em>frame</em>. The first entry in the returned list represents <em>frame</em>; the last entry represents the outermost call on <em>frame</em>‘s stack.</p> </dd></dl> <dl class="function"> <dt id="inspect.getinnerframes"> <tt class="descclassname">inspect.</tt><tt class="descname">getinnerframes</tt><big>(</big><em>traceback</em><span class="optional">[</span>, <em>context</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#inspect.getinnerframes" title="Permalink to this definition">¶</a></dt> <dd><p>Get a list of frame records for a traceback’s frame and all inner frames. These frames represent calls made as a consequence of <em>frame</em>. The first entry in the list represents <em>traceback</em>; the last entry represents where the exception was raised.</p> </dd></dl> <dl class="function"> <dt id="inspect.currentframe"> <tt class="descclassname">inspect.</tt><tt class="descname">currentframe</tt><big>(</big><big>)</big><a class="headerlink" href="#inspect.currentframe" title="Permalink to this definition">¶</a></dt> <dd><p>Return the frame object for the caller’s stack frame.</p> <div class="impl-detail compound"> <p><strong>CPython implementation detail:</strong> This function relies on Python stack frame support in the interpreter, which isn’t guaranteed to exist in all implementations of Python. If running in an implementation without Python stack frame support this function returns <tt class="docutils literal"><span class="pre">None</span></tt>.</p> </div> </dd></dl> <dl class="function"> <dt id="inspect.stack"> <tt class="descclassname">inspect.</tt><tt class="descname">stack</tt><big>(</big><span class="optional">[</span><em>context</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#inspect.stack" title="Permalink to this definition">¶</a></dt> <dd><p>Return a list of frame records for the caller’s stack. The first entry in the returned list represents the caller; the last entry represents the outermost call on the stack.</p> </dd></dl> <dl class="function"> <dt id="inspect.trace"> <tt class="descclassname">inspect.</tt><tt class="descname">trace</tt><big>(</big><span class="optional">[</span><em>context</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#inspect.trace" title="Permalink to this definition">¶</a></dt> <dd><p>Return a list of frame records for the stack between the current frame and the frame in which an exception currently being handled was raised in. The first entry in the list represents the caller; the last entry represents where the exception was raised.</p> </dd></dl> </div> </div> </div> </div> </div> <div class="sphinxsidebar"> <div class="sphinxsidebarwrapper"> <h3><a href="../contents.html">Table Of Contents</a></h3> <ul> <li><a class="reference internal" href="#">27.13. <tt class="docutils literal"><span class="pre">inspect</span></tt> — Inspect live objects</a><ul> <li><a class="reference internal" href="#types-and-members">27.13.1. Types and members</a></li> <li><a class="reference internal" href="#retrieving-source-code">27.13.2. Retrieving source code</a></li> <li><a class="reference internal" href="#classes-and-functions">27.13.3. Classes and functions</a></li> <li><a class="reference internal" href="#the-interpreter-stack">27.13.4. The interpreter stack</a></li> </ul> </li> </ul> <h4>Previous topic</h4> <p class="topless"><a href="gc.html" title="previous chapter">27.12. <tt class="docutils literal"><span class="pre">gc</span></tt> — Garbage Collector interface</a></p> <h4>Next topic</h4> <p class="topless"><a href="site.html" title="next chapter">27.14. <tt class="docutils literal"><span class="pre">site</span></tt> — Site-specific configuration hook</a></p> <h3>This Page</h3> <ul class="this-page-menu"> <li><a href="../bugs.html">Report a Bug</a></li> <li><a href="../_sources/library/inspect.txt" rel="nofollow">Show Source</a></li> </ul> <div id="searchbox" style="display: none"> <h3>Quick search</h3> <form class="search" action="../search.html" method="get"> <input type="text" name="q" /> <input type="submit" value="Go" /> <input type="hidden" name="check_keywords" value="yes" /> <input type="hidden" name="area" value="default" /> </form> <p class="searchtip" style="font-size: 90%"> Enter search terms or a module, class or function name. </p> </div> <script type="text/javascript">$('#searchbox').show(0);</script> </div> </div> <div class="clearer"></div> </div> <div class="related"> <h3>Navigation</h3> <ul> <li class="right" style="margin-right: 10px"> <a href="../genindex.html" title="General Index" >index</a></li> <li class="right" > <a href="../py-modindex.html" title="Python Module Index" >modules</a> |</li> <li class="right" > <a href="site.html" title="27.14. site — Site-specific configuration hook" >next</a> |</li> <li class="right" > <a href="gc.html" title="27.12. gc — Garbage Collector interface" >previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="http://www.python.org/">Python</a> »</li> <li> <a href="../index.html">Python 2.7.5 documentation</a> » </li> <li><a href="index.html" >The Python Standard Library</a> »</li> <li><a href="python.html" >27. Python Runtime Services</a> »</li> </ul> </div> <div class="footer"> © <a href="../copyright.html">Copyright</a> 1990-2020, Python Software Foundation. <br /> The Python Software Foundation is a non-profit corporation. <a href="http://www.python.org/psf/donations/">Please donate.</a> <br /> Last updated on Oct 13, 2020. <a href="../bugs.html">Found a bug</a>? <br /> Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 1.1.3. </div> </body> </html>