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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"> <h1>27.11. <tt class="xref docutils literal"><span class="pre">inspect</span></tt> — Inspect live objects<a class="headerlink" href="#module-inspect" title="Permalink to this headline">¶</a></h1> <p>The <tt class="xref docutils literal"><span class="pre">inspect</span></tt> 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>27.11.1. Types and members<a class="headerlink" href="#types-and-members" title="Permalink to this headline">¶</a></h2> <p>The <a title="inspect.getmembers" class="reference internal" href="#inspect.getmembers"><tt class="xref 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 title="inspect.getmembers" class="reference internal" href="#inspect.getmembers"><tt class="xref 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="20%" /> <col width="31%" /> <col width="49%" /> </colgroup> <thead valign="bottom"> <tr><th class="head">Type</th> <th class="head">Attribute</th> <th class="head">Description</th> </tr> </thead> <tbody valign="top"> <tr><td>module</td> <td>__doc__</td> <td>documentation string</td> </tr> <tr><td> </td> <td>__file__</td> <td>filename (missing for built-in modules)</td> </tr> <tr><td>class</td> <td>__doc__</td> <td>documentation string</td> </tr> <tr><td> </td> <td>__module__</td> <td>name of module in which this class was defined</td> </tr> <tr><td>method</td> <td>__doc__</td> <td>documentation string</td> </tr> <tr><td> </td> <td>__name__</td> <td>name with which this method was defined</td> </tr> <tr><td> </td> <td>__func__</td> <td>function object containing implementation of method</td> </tr> <tr><td> </td> <td>__self__</td> <td>instance to which this method is bound, or <tt class="xref docutils literal"><span class="pre">None</span></tt></td> </tr> <tr><td>function</td> <td>__doc__</td> <td>documentation string</td> </tr> <tr><td> </td> <td>__name__</td> <td>name with which this function was defined</td> </tr> <tr><td> </td> <td>__code__</td> <td>code object containing compiled function <a class="reference external" href="../glossary.html#term-bytecode"><em class="xref">bytecode</em></a></td> </tr> <tr><td> </td> <td>__defaults__</td> <td>tuple of any default values for arguments</td> </tr> <tr><td> </td> <td>__globals__</td> <td>global namespace in which this function was defined</td> </tr> <tr><td>traceback</td> <td>tb_frame</td> <td>frame object at this level</td> </tr> <tr><td> </td> <td>tb_lasti</td> <td>index of last attempted instruction in bytecode</td> </tr> <tr><td> </td> <td>tb_lineno</td> <td>current line number in Python source code</td> </tr> <tr><td> </td> <td>tb_next</td> <td>next inner traceback object (called by this level)</td> </tr> <tr><td>frame</td> <td>f_back</td> <td>next outer frame object (this frame’s caller)</td> </tr> <tr><td> </td> <td>f_builtins</td> <td>built-in namespace seen by this frame</td> </tr> <tr><td> </td> <td>f_code</td> <td>code object being executed in this frame</td> </tr> <tr><td> </td> <td>f_globals</td> <td>global namespace seen by this frame</td> </tr> <tr><td> </td> <td>f_lasti</td> <td>index of last attempted instruction in bytecode</td> </tr> <tr><td> </td> <td>f_lineno</td> <td>current line number in Python source code</td> </tr> <tr><td> </td> <td>f_locals</td> <td>local namespace seen by this frame</td> </tr> <tr><td> </td> <td>f_restricted</td> <td>0 or 1 if frame is in restricted execution mode</td> </tr> <tr><td> </td> <td>f_trace</td> <td>tracing function for this frame, or <tt class="xref docutils literal"><span class="pre">None</span></tt></td> </tr> <tr><td>code</td> <td>co_argcount</td> <td>number of arguments (not including * or ** args)</td> </tr> <tr><td> </td> <td>co_code</td> <td>string of raw compiled bytecode</td> </tr> <tr><td> </td> <td>co_consts</td> <td>tuple of constants used in the bytecode</td> </tr> <tr><td> </td> <td>co_filename</td> <td>name of file in which this code object was created</td> </tr> <tr><td> </td> <td>co_firstlineno</td> <td>number of first line in Python source code</td> </tr> <tr><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> </tr> <tr><td> </td> <td>co_lnotab</td> <td>encoded mapping of line numbers to bytecode indices</td> </tr> <tr><td> </td> <td>co_name</td> <td>name with which this code object was defined</td> </tr> <tr><td> </td> <td>co_names</td> <td>tuple of names of local variables</td> </tr> <tr><td> </td> <td>co_nlocals</td> <td>number of local variables</td> </tr> <tr><td> </td> <td>co_stacksize</td> <td>virtual machine stack space required</td> </tr> <tr><td> </td> <td>co_varnames</td> <td>tuple of names of arguments and local variables</td> </tr> <tr><td>builtin</td> <td>__doc__</td> <td>documentation string</td> </tr> <tr><td> </td> <td>__name__</td> <td>original name of this function or method</td> </tr> <tr><td> </td> <td>__self__</td> <td>instance to which a method is bound, or <tt class="xref docutils literal"><span class="pre">None</span></tt></td> </tr> </tbody> </table> <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 title="inspect.getmembers" class="reference internal" href="#inspect.getmembers"><tt class="xref 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 title="dir" class="reference external" href="functions.html#dir"><tt class="xref 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>Returns a <a class="reference external" href="../glossary.html#term-named-tuple"><em class="xref">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> of values that describe how Python will interpret the file identified by <em>path</em> if it is a module, or <tt class="xref 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">mtype)</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 title="open" class="reference external" href="functions.html#open"><tt class="xref 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>mtype</em> is an integer giving the type of the module. <em>mtype</em> will have a value which can be compared to the constants defined in the <a title="Access the implementation of the import statement." class="reference external" href="imp.html#module-imp"><tt class="xref docutils literal"><span class="pre">imp</span></tt></a> module; see the documentation for that module for more information on module types.</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>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="xref docutils literal"><span class="pre">None</span></tt> is returned.</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>Return true if the object is a module.</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>Return true if the object is a class.</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>Return true if the object is a method.</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>Return true if the object is a Python function or unnamed (<a class="reference external" href="../glossary.html#term-lambda"><em class="xref">lambda</em></a>) function.</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>Return true if the object is a Python generator function.</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>Return true if the object is a generator.</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>Return true if the object is a traceback.</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>Return true if the object is a frame.</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>Return true if the object is a code.</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>Return true if the object is a built-in function.</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>Return true if the object is a user-defined or built-in function or method.</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>Return true if the object is an abstract base class.</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 title="inspect.ismethod" class="reference internal" href="#inspect.ismethod"><tt class="xref docutils literal"><span class="pre">ismethod()</span></tt></a> or <a title="inspect.isclass" class="reference internal" href="#inspect.isclass"><tt class="xref docutils literal"><span class="pre">isclass()</span></tt></a> or <a title="inspect.isfunction" class="reference internal" href="#inspect.isfunction"><tt class="xref docutils literal"><span class="pre">isfunction()</span></tt></a> are true.</p> <p>This, 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 docutils literal"><span class="pre">__get__</span></tt> attribute but not a <tt class="xref docutils literal"><span class="pre">__set__</span></tt> attribute, but beyond that the set of attributes varies. <tt class="xref docutils literal"><span class="pre">__name__</span></tt> is usually sensible, and <tt class="xref 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 title="inspect.ismethoddescriptor" class="reference internal" href="#inspect.ismethoddescriptor"><tt class="xref 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 docutils literal"><span class="pre">__func__</span></tt> attribute (etc) when an object passes <a title="inspect.ismethod" class="reference internal" href="#inspect.ismethod"><tt class="xref 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 docutils literal"><span class="pre">__get__</span></tt> and a <tt class="xref 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 docutils literal"><span class="pre">__name__</span></tt> and <tt class="xref docutils literal"><span class="pre">__doc__</span></tt> attributes (properties, getsets, and members have both of these attributes), but this is not guaranteed.</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> <p>getsets are attributes defined in extension modules via <tt class="docutils literal"><span class="pre">PyGetSetDef</span></tt> structures. For Python implementations without such types, this method will always return <tt class="xref docutils literal"><span class="pre">False</span></tt>.</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> <p>Member descriptors are attributes defined in extension modules via <tt class="docutils literal"><span class="pre">PyMemberDef</span></tt> structures. For Python implementations without such types, this method will always return <tt class="xref docutils literal"><span class="pre">False</span></tt>.</p> </dd></dl> </div> <div class="section" id="retrieving-source-code"> <span id="inspect-source"></span><h2>27.11.2. 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>Get the documentation string for an object, cleaned up with <a title="inspect.cleandoc" class="reference internal" href="#inspect.cleandoc"><tt class="xref docutils literal"><span class="pre">cleandoc()</span></tt></a>.</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>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).</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>Return the name of the (text or binary) file in which an object was defined. This will fail with a <a title="exceptions.TypeError" class="reference external" href="exceptions.html#exceptions.TypeError"><tt class="xref docutils literal"><span class="pre">TypeError</span></tt></a> if the object is a built-in module, class, or function.</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>Try to guess which module an object was defined in.</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>Return the name of the Python source file in which an object was defined. This will fail with a <a title="exceptions.TypeError" class="reference external" href="exceptions.html#exceptions.TypeError"><tt class="xref docutils literal"><span class="pre">TypeError</span></tt></a> if the object is a built-in module, class, or function.</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>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 title="exceptions.IOError" class="reference external" href="exceptions.html#exceptions.IOError"><tt class="xref docutils literal"><span class="pre">IOError</span></tt></a> is raised if the source code cannot be retrieved.</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>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 title="exceptions.IOError" class="reference external" href="exceptions.html#exceptions.IOError"><tt class="xref docutils literal"><span class="pre">IOError</span></tt></a> is raised if the source code cannot be retrieved.</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>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.</dd></dl> </div> <div class="section" id="classes-and-functions"> <span id="inspect-classes-functions"></span><h2>27.11.3. 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>, <em>unique=False</em><big>)</big><a class="headerlink" href="#inspect.getclasstree" title="Permalink to this definition">¶</a></dt> <dd>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.</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 function’s arguments. A <a class="reference external" href="../glossary.html#term-named-tuple"><em class="xref">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> is returned. <em>args</em> is a list of the argument names. <em>varargs</em> and <em>varkw</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="xref 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> <span class="versionmodified">Deprecated since version 3.0: </span>Use <a title="inspect.getfullargspec" class="reference internal" href="#inspect.getfullargspec"><tt class="xref docutils literal"><span class="pre">getfullargspec()</span></tt></a> instead, which provides information about keyword-only arguments and annotations.</p> </dd></dl> <dl class="function"> <dt id="inspect.getfullargspec"> <tt class="descclassname">inspect.</tt><tt class="descname">getfullargspec</tt><big>(</big><em>func</em><big>)</big><a class="headerlink" href="#inspect.getfullargspec" title="Permalink to this definition">¶</a></dt> <dd><p>Get the names and default values of a function’s arguments. A <a class="reference external" href="../glossary.html#term-named-tuple"><em class="xref">named tuple</em></a> is returned:</p> <p><tt class="docutils literal"><span class="pre">FullArgSpec(args,</span> <span class="pre">varargs,</span> <span class="pre">varkw,</span> <span class="pre">defaults,</span> <span class="pre">kwonlyargs,</span> <span class="pre">kwonlydefaults,</span> <span class="pre">annotations)</span></tt></p> <p><em>args</em> is a list of the argument names. <em>varargs</em> and <em>varkw</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="xref docutils literal"><span class="pre">None</span></tt>. <em>defaults</em> is an n-tuple of the default values of the last n arguments. <em>kwonlyargs</em> is a list of keyword-only argument names. <em>kwonlydefaults</em> is a dictionary mapping names from kwonlyargs to defaults. <em>annotations</em> is a dictionary mapping argument names to annotations.</p> <p>The first four items in the tuple correspond to <a title="inspect.getargspec" class="reference internal" href="#inspect.getargspec"><tt class="xref docutils literal"><span class="pre">getargspec()</span></tt></a>.</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>Get information about arguments passed into a particular frame. A <a class="reference external" href="../glossary.html#term-named-tuple"><em class="xref">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> is returned. <em>args</em> is a list of the argument names (it may contain nested lists). <em>varargs</em> and <em>varkw</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="xref docutils literal"><span class="pre">None</span></tt>. <em>locals</em> is the locals dictionary of the given frame.</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>Format a pretty argument spec from the four values returned by <a title="inspect.getargspec" class="reference internal" href="#inspect.getargspec"><tt class="xref 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.</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>Format a pretty argument spec from the four values returned by <a title="inspect.getargvalues" class="reference internal" href="#inspect.getargvalues"><tt class="xref 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.</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>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.</dd></dl> </div> <div class="section" id="the-interpreter-stack"> <span id="inspect-stack"></span><h2>27.11.4. 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 external" href="../reference/compound_stmts.html#finally"><tt class="xref 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 title="gc.disable" class="reference external" href="gc.html#gc.disable"><tt class="xref docutils literal"><span class="pre">gc.disable()</span></tt></a>. For example:</p> <div class="last highlight-python3"><div class="highlight"><pre><span class="k">def</span> <span class="nf">handle_stackframe_without_leak</span><span class="p">():</span> <span class="n">frame</span> <span class="o">=</span> <span class="n">inspect</span><span class="o">.</span><span class="n">currentframe</span><span class="p">()</span> <span class="k">try</span><span class="p">:</span> <span class="c"># do something with the frame</span> <span class="k">finally</span><span class="p">:</span> <span class="k">del</span> <span class="n">frame</span> </pre></div> </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>, <em>context=1</em><big>)</big><a class="headerlink" href="#inspect.getframeinfo" title="Permalink to this definition">¶</a></dt> <dd>Get information about a frame or traceback object. A <a class="reference external" href="../glossary.html#term-named-tuple"><em class="xref">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> is returned.</dd></dl> <dl class="function"> <dt id="inspect.getouterframes"> <tt class="descclassname">inspect.</tt><tt class="descname">getouterframes</tt><big>(</big><em>frame</em>, <em>context=1</em><big>)</big><a class="headerlink" href="#inspect.getouterframes" title="Permalink to this definition">¶</a></dt> <dd>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.</dd></dl> <dl class="function"> <dt id="inspect.getinnerframes"> <tt class="descclassname">inspect.</tt><tt class="descname">getinnerframes</tt><big>(</big><em>traceback</em>, <em>context=1</em><big>)</big><a class="headerlink" href="#inspect.getinnerframes" title="Permalink to this definition">¶</a></dt> <dd>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.</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>Return the frame object for the caller’s stack frame.</dd></dl> <dl class="function"> <dt id="inspect.stack"> <tt class="descclassname">inspect.</tt><tt class="descname">stack</tt><big>(</big><em>context=1</em><big>)</big><a class="headerlink" href="#inspect.stack" title="Permalink to this definition">¶</a></dt> <dd>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.</dd></dl> <dl class="function"> <dt id="inspect.trace"> <tt class="descclassname">inspect.</tt><tt class="descname">trace</tt><big>(</big><em>context=1</em><big>)</big><a class="headerlink" href="#inspect.trace" title="Permalink to this definition">¶</a></dt> <dd>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.</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 external" href="">27.11. <tt class="docutils literal"><span class="pre">inspect</span></tt> — Inspect live objects</a><ul> <li><a class="reference external" href="#types-and-members">27.11.1. Types and members</a></li> <li><a class="reference external" href="#retrieving-source-code">27.11.2. Retrieving source code</a></li> <li><a class="reference external" href="#classes-and-functions">27.11.3. Classes and functions</a></li> <li><a class="reference external" href="#the-interpreter-stack">27.11.4. The interpreter stack</a></li> </ul> </li> </ul> <h4>Previous topic</h4> <p class="topless"><a href="gc.html" title="previous chapter">27.10. <tt class="docutils literal docutils literal 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">27.12. <tt class="docutils literal 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="../_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" size="18" /> <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="../modindex.html" title="Global Module Index" >modules</a> |</li> <li class="right" > <a href="site.html" title="27.12. site — Site-specific configuration hook" >next</a> |</li> <li class="right" > <a href="gc.html" title="27.10. 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="../index.html">Python v3.1.1 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> 1990-2009, 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 Aug 16, 2009. Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 0.6.2. </div> </body> </html>