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Importing Modules</a> »</li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body"> <div class="section" id="module-importlib"> <span id="importlib-an-implementation-of-import"></span><h1>30.6. <a class="reference internal" href="#module-importlib" title="importlib: An implementation of the import machinery."><tt class="xref py py-mod docutils literal"><span class="pre">importlib</span></tt></a> – An implementation of <a class="reference internal" href="../reference/simple_stmts.html#import"><tt class="xref std std-keyword docutils literal"><span class="pre">import</span></tt></a><a class="headerlink" href="#module-importlib" title="Permalink to this headline">¶</a></h1> <p class="versionadded"> <span class="versionmodified">New in version 3.1.</span> </p> <div class="section" id="introduction"> <h2>30.6.1. Introduction<a class="headerlink" href="#introduction" title="Permalink to this headline">¶</a></h2> <p>The purpose of the <a class="reference internal" href="#module-importlib" title="importlib: An implementation of the import machinery."><tt class="xref py py-mod docutils literal"><span class="pre">importlib</span></tt></a> package is two-fold. One is to provide an implementation of the <a class="reference internal" href="../reference/simple_stmts.html#import"><tt class="xref std std-keyword docutils literal"><span class="pre">import</span></tt></a> statement (and thus, by extension, the <a class="reference internal" href="functions.html#__import__" title="__import__"><tt class="xref py py-func docutils literal"><span class="pre">__import__()</span></tt></a> function) in Python source code. This provides an implementation of <a class="reference internal" href="../reference/simple_stmts.html#import"><tt class="xref std std-keyword docutils literal"><span class="pre">import</span></tt></a> which is portable to any Python interpreter. This also provides a reference implementation which is easier to comprehend than one implemented in a programming language other than Python.</p> <p>Two, the components to implement <a class="reference internal" href="../reference/simple_stmts.html#import"><tt class="xref std std-keyword docutils literal"><span class="pre">import</span></tt></a> are exposed in this package, making it easier for users to create their own custom objects (known generically as an <a class="reference internal" href="../glossary.html#term-importer"><em class="xref std std-term">importer</em></a>) to participate in the import process. Details on custom importers can be found in <span class="target" id="index-0"></span><a class="pep reference external" href="http://www.python.org/dev/peps/pep-0302"><strong>PEP 302</strong></a>.</p> <div class="admonition-see-also admonition seealso"> <p class="first admonition-title">See also</p> <dl class="last docutils"> <dt><a class="reference internal" href="../reference/simple_stmts.html#import"><em>The import statement</em></a></dt> <dd>The language reference for the <a class="reference internal" href="../reference/simple_stmts.html#import"><tt class="xref std std-keyword docutils literal"><span class="pre">import</span></tt></a> statement.</dd> <dt><a class="reference external" href="http://www.python.org/doc/essays/packages.html">Packages specification</a></dt> <dd>Original specification of packages. Some semantics have changed since the writing of this document (e.g. redirecting based on <tt class="xref docutils literal"><span class="pre">None</span></tt> in <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><tt class="xref py py-data docutils literal"><span class="pre">sys.modules</span></tt></a>).</dd> <dt>The <a class="reference internal" href="#importlib.__import__" title="importlib.__import__"><tt class="xref py py-func docutils literal"><span class="pre">__import__()</span></tt></a> function</dt> <dd>The <a class="reference internal" href="../reference/simple_stmts.html#import"><tt class="xref std std-keyword docutils literal"><span class="pre">import</span></tt></a> statement is syntactic sugar for this function.</dd> <dt><span class="target" id="index-1"></span><a class="pep reference external" href="http://www.python.org/dev/peps/pep-0235"><strong>PEP 235</strong></a></dt> <dd>Import on Case-Insensitive Platforms</dd> <dt><span class="target" id="index-2"></span><a class="pep reference external" href="http://www.python.org/dev/peps/pep-0263"><strong>PEP 263</strong></a></dt> <dd>Defining Python Source Code Encodings</dd> <dt><span class="target" id="index-3"></span><a class="pep reference external" href="http://www.python.org/dev/peps/pep-0302"><strong>PEP 302</strong></a></dt> <dd>New Import Hooks</dd> <dt><span class="target" id="index-4"></span><a class="pep reference external" href="http://www.python.org/dev/peps/pep-0328"><strong>PEP 328</strong></a></dt> <dd>Imports: Multi-Line and Absolute/Relative</dd> <dt><span class="target" id="index-5"></span><a class="pep reference external" href="http://www.python.org/dev/peps/pep-0366"><strong>PEP 366</strong></a></dt> <dd>Main module explicit relative imports</dd> <dt><span class="target" id="index-6"></span><a class="pep reference external" href="http://www.python.org/dev/peps/pep-3120"><strong>PEP 3120</strong></a></dt> <dd>Using UTF-8 as the Default Source Encoding</dd> <dt><span class="target" id="index-7"></span><a class="pep reference external" href="http://www.python.org/dev/peps/pep-3147"><strong>PEP 3147</strong></a></dt> <dd>PYC Repository Directories</dd> </dl> </div> </div> <div class="section" id="functions"> <h2>30.6.2. Functions<a class="headerlink" href="#functions" title="Permalink to this headline">¶</a></h2> <dl class="function"> <dt id="importlib.__import__"> <tt class="descclassname">importlib.</tt><tt class="descname">__import__</tt><big>(</big><em>name</em>, <em>globals=None</em>, <em>locals=None</em>, <em>fromlist=()</em>, <em>level=0</em><big>)</big><a class="headerlink" href="#importlib.__import__" title="Permalink to this definition">¶</a></dt> <dd><p>An implementation of the built-in <a class="reference internal" href="functions.html#__import__" title="__import__"><tt class="xref py py-func docutils literal"><span class="pre">__import__()</span></tt></a> function.</p> </dd></dl> <dl class="function"> <dt id="importlib.import_module"> <tt class="descclassname">importlib.</tt><tt class="descname">import_module</tt><big>(</big><em>name</em>, <em>package=None</em><big>)</big><a class="headerlink" href="#importlib.import_module" title="Permalink to this definition">¶</a></dt> <dd><p>Import a module. The <em>name</em> argument specifies what module to import in absolute or relative terms (e.g. either <tt class="docutils literal"><span class="pre">pkg.mod</span></tt> or <tt class="docutils literal"><span class="pre">..mod</span></tt>). If the name is specified in relative terms, then the <em>package</em> argument must be set to the name of the package which is to act as the anchor for resolving the package name (e.g. <tt class="docutils literal"><span class="pre">import_module('..mod',</span> <span class="pre">'pkg.subpkg')</span></tt> will import <tt class="docutils literal"><span class="pre">pkg.mod</span></tt>).</p> <p>The <a class="reference internal" href="#importlib.import_module" title="importlib.import_module"><tt class="xref py py-func docutils literal"><span class="pre">import_module()</span></tt></a> function acts as a simplifying wrapper around <a class="reference internal" href="#importlib.__import__" title="importlib.__import__"><tt class="xref py py-func docutils literal"><span class="pre">importlib.__import__()</span></tt></a>. This means all semantics of the function are derived from <a class="reference internal" href="#importlib.__import__" title="importlib.__import__"><tt class="xref py py-func docutils literal"><span class="pre">importlib.__import__()</span></tt></a>, including requiring the package from which an import is occurring to have been previously imported (i.e., <em>package</em> must already be imported). The most important difference is that <a class="reference internal" href="#importlib.import_module" title="importlib.import_module"><tt class="xref py py-func docutils literal"><span class="pre">import_module()</span></tt></a> returns the most nested package or module that was imported (e.g. <tt class="docutils literal"><span class="pre">pkg.mod</span></tt>), while <a class="reference internal" href="functions.html#__import__" title="__import__"><tt class="xref py py-func docutils literal"><span class="pre">__import__()</span></tt></a> returns the top-level package or module (e.g. <tt class="docutils literal"><span class="pre">pkg</span></tt>).</p> </dd></dl> <dl class="function"> <dt id="importlib.find_loader"> <tt class="descclassname">importlib.</tt><tt class="descname">find_loader</tt><big>(</big><em>name</em>, <em>path=None</em><big>)</big><a class="headerlink" href="#importlib.find_loader" title="Permalink to this definition">¶</a></dt> <dd><p>Find the loader for a module, optionally within the specified <em>path</em>. If the module is in <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><tt class="xref py py-attr docutils literal"><span class="pre">sys.modules</span></tt></a>, then <tt class="docutils literal"><span class="pre">sys.modules[name].__loader__</span></tt> is returned (unless the loader would be <tt class="xref docutils literal"><span class="pre">None</span></tt>, in which case <a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><tt class="xref py py-exc docutils literal"><span class="pre">ValueError</span></tt></a> is raised). Otherwise a search using <a class="reference internal" href="sys.html#sys.meta_path" title="sys.meta_path"><tt class="xref py py-attr docutils literal"><span class="pre">sys.meta_path</span></tt></a> is done. <tt class="xref docutils literal"><span class="pre">None</span></tt> is returned if no loader is found.</p> <p>A dotted name does not have its parent’s implicitly imported. If that is desired (although not nessarily required to find the loader, it will most likely be needed if the loader actually is used to load the module), then you will have to import the packages containing the module prior to calling this function.</p> </dd></dl> <dl class="function"> <dt id="importlib.invalidate_caches"> <tt class="descclassname">importlib.</tt><tt class="descname">invalidate_caches</tt><big>(</big><big>)</big><a class="headerlink" href="#importlib.invalidate_caches" title="Permalink to this definition">¶</a></dt> <dd><p>Invalidate the internal caches of finders stored at <a class="reference internal" href="sys.html#sys.meta_path" title="sys.meta_path"><tt class="xref py py-data docutils literal"><span class="pre">sys.meta_path</span></tt></a>. If a finder implements <tt class="docutils literal"><span class="pre">invalidate_caches()</span></tt> then it will be called to perform the invalidation. This function may be needed if some modules are installed while your program is running and you expect the program to notice the changes.</p> <p class="versionadded"> <span class="versionmodified">New in version 3.3.</span> </p> </dd></dl> </div> <div class="section" id="module-importlib.abc"> <span id="importlib-abc-abstract-base-classes-related-to-import"></span><h2>30.6.3. <a class="reference internal" href="#module-importlib.abc" title="importlib.abc: Abstract base classes related to import"><tt class="xref py py-mod docutils literal"><span class="pre">importlib.abc</span></tt></a> – Abstract base classes related to import<a class="headerlink" href="#module-importlib.abc" title="Permalink to this headline">¶</a></h2> <p>The <a class="reference internal" href="#module-importlib.abc" title="importlib.abc: Abstract base classes related to import"><tt class="xref py py-mod docutils literal"><span class="pre">importlib.abc</span></tt></a> module contains all of the core abstract base classes used by <a class="reference internal" href="../reference/simple_stmts.html#import"><tt class="xref std std-keyword docutils literal"><span class="pre">import</span></tt></a>. Some subclasses of the core abstract base classes are also provided to help in implementing the core ABCs.</p> <p>ABC hierarchy:</p> <div class="highlight-python3"><div class="highlight"><pre><span class="nb">object</span> <span class="o">+--</span> <span class="n">Finder</span> <span class="p">(</span><span class="n">deprecated</span><span class="p">)</span> <span class="o">|</span> <span class="o">+--</span> <span class="n">MetaPathFinder</span> <span class="o">|</span> <span class="o">+--</span> <span class="n">PathEntryFinder</span> <span class="o">+--</span> <span class="n">Loader</span> <span class="o">+--</span> <span class="n">ResourceLoader</span> <span class="o">--------+</span> <span class="o">+--</span> <span class="n">InspectLoader</span> <span class="o">|</span> <span class="o">+--</span> <span class="n">ExecutionLoader</span> <span class="o">--+</span> <span class="o">+--</span> <span class="n">FileLoader</span> <span class="o">+--</span> <span class="n">SourceLoader</span> <span class="o">+--</span> <span class="n">PyLoader</span> <span class="p">(</span><span class="n">deprecated</span><span class="p">)</span> <span class="o">+--</span> <span class="n">PyPycLoader</span> <span class="p">(</span><span class="n">deprecated</span><span class="p">)</span> </pre></div> </div> <dl class="class"> <dt id="importlib.abc.Finder"> <em class="property">class </em><tt class="descclassname">importlib.abc.</tt><tt class="descname">Finder</tt><a class="headerlink" href="#importlib.abc.Finder" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract base class representing a <a class="reference internal" href="../glossary.html#term-finder"><em class="xref std std-term">finder</em></a>.</p> <p class="deprecated"> <span class="versionmodified">Deprecated since version 3.3:</span> Use <a class="reference internal" href="#importlib.abc.MetaPathFinder" title="importlib.abc.MetaPathFinder"><tt class="xref py py-class docutils literal"><span class="pre">MetaPathFinder</span></tt></a> or <a class="reference internal" href="#importlib.abc.PathEntryFinder" title="importlib.abc.PathEntryFinder"><tt class="xref py py-class docutils literal"><span class="pre">PathEntryFinder</span></tt></a> instead.</p> <dl class="method"> <dt id="importlib.abc.Finder.find_module"> <tt class="descname">find_module</tt><big>(</big><em>fullname</em>, <em>path=None</em><big>)</big><a class="headerlink" href="#importlib.abc.Finder.find_module" title="Permalink to this definition">¶</a></dt> <dd><p>An abstact method for finding a <a class="reference internal" href="../glossary.html#term-loader"><em class="xref std std-term">loader</em></a> for the specified module. Originally specified in <span class="target" id="index-8"></span><a class="pep reference external" href="http://www.python.org/dev/peps/pep-0302"><strong>PEP 302</strong></a>, this method was meant for use in <a class="reference internal" href="sys.html#sys.meta_path" title="sys.meta_path"><tt class="xref py py-data docutils literal"><span class="pre">sys.meta_path</span></tt></a> and in the path-based import subsystem.</p> </dd></dl> </dd></dl> <dl class="class"> <dt id="importlib.abc.MetaPathFinder"> <em class="property">class </em><tt class="descclassname">importlib.abc.</tt><tt class="descname">MetaPathFinder</tt><a class="headerlink" href="#importlib.abc.MetaPathFinder" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract base class representing a <a class="reference internal" href="../glossary.html#term-meta-path-finder"><em class="xref std std-term">meta path finder</em></a>. For compatibility, this is a subclass of <a class="reference internal" href="#importlib.abc.Finder" title="importlib.abc.Finder"><tt class="xref py py-class docutils literal"><span class="pre">Finder</span></tt></a>.</p> <p class="versionadded"> <span class="versionmodified">New in version 3.3.</span> </p> <dl class="method"> <dt id="importlib.abc.MetaPathFinder.find_module"> <tt class="descname">find_module</tt><big>(</big><em>fullname</em>, <em>path</em><big>)</big><a class="headerlink" href="#importlib.abc.MetaPathFinder.find_module" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract method for finding a <a class="reference internal" href="../glossary.html#term-loader"><em class="xref std std-term">loader</em></a> for the specified module. If this is a top-level import, <em>path</em> will be <tt class="xref docutils literal"><span class="pre">None</span></tt>. Otheriwse, this is a search for a subpackage or module and <em>path</em> will be the value of <tt class="xref py py-attr docutils literal"><span class="pre">__path__</span></tt> from the parent package. If a loader cannot be found, <tt class="xref docutils literal"><span class="pre">None</span></tt> is returned.</p> </dd></dl> <dl class="method"> <dt id="importlib.abc.MetaPathFinder.invalidate_caches"> <tt class="descname">invalidate_caches</tt><big>(</big><big>)</big><a class="headerlink" href="#importlib.abc.MetaPathFinder.invalidate_caches" title="Permalink to this definition">¶</a></dt> <dd><p>An optional method which, when called, should invalidate any internal cache used by the finder. Used by <a class="reference internal" href="#importlib.invalidate_caches" title="importlib.invalidate_caches"><tt class="xref py py-func docutils literal"><span class="pre">importlib.invalidate_caches()</span></tt></a> when invalidating the caches of all finders on <a class="reference internal" href="sys.html#sys.meta_path" title="sys.meta_path"><tt class="xref py py-data docutils literal"><span class="pre">sys.meta_path</span></tt></a>.</p> </dd></dl> </dd></dl> <dl class="class"> <dt id="importlib.abc.PathEntryFinder"> <em class="property">class </em><tt class="descclassname">importlib.abc.</tt><tt class="descname">PathEntryFinder</tt><a class="headerlink" href="#importlib.abc.PathEntryFinder" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract base class representing a <a class="reference internal" href="../glossary.html#term-path-entry-finder"><em class="xref std std-term">path entry finder</em></a>. Though it bears some similarities to <a class="reference internal" href="#importlib.abc.MetaPathFinder" title="importlib.abc.MetaPathFinder"><tt class="xref py py-class docutils literal"><span class="pre">MetaPathFinder</span></tt></a>, <tt class="docutils literal"><span class="pre">PathEntryFinder</span></tt> is meant for use only within the path-based import subsystem provided by <tt class="xref py py-class docutils literal"><span class="pre">PathFinder</span></tt>. This ABC is a subclass of <a class="reference internal" href="#importlib.abc.Finder" title="importlib.abc.Finder"><tt class="xref py py-class docutils literal"><span class="pre">Finder</span></tt></a> for compatibility.</p> <p class="versionadded"> <span class="versionmodified">New in version 3.3.</span> </p> <dl class="method"> <dt> <tt class="descname">find_loader(fullname):</tt></dt> <dd><p>An abstract method for finding a <a class="reference internal" href="../glossary.html#term-loader"><em class="xref std std-term">loader</em></a> for the specified module. Returns a 2-tuple of <tt class="docutils literal"><span class="pre">(loader,</span> <span class="pre">portion)</span></tt> where <tt class="docutils literal"><span class="pre">portion</span></tt> is a sequence of file system locations contributing to part of a namespace package. The loader may be <tt class="xref docutils literal"><span class="pre">None</span></tt> while specifying <tt class="docutils literal"><span class="pre">portion</span></tt> to signify the contribution of the file system locations to a namespace package. An empty list can be used for <tt class="docutils literal"><span class="pre">portion</span></tt> to signify the loader is not part of a package. If <tt class="docutils literal"><span class="pre">loader</span></tt> is <tt class="xref docutils literal"><span class="pre">None</span></tt> and <tt class="docutils literal"><span class="pre">portion</span></tt> is the empty list then no loader or location for a namespace package were found (i.e. failure to find anything for the module).</p> </dd></dl> <dl class="method"> <dt> <tt class="descname">find_module(fullname):</tt></dt> <dd><p>A concrete implementation of <a class="reference internal" href="#importlib.abc.Finder.find_module" title="importlib.abc.Finder.find_module"><tt class="xref py py-meth docutils literal"><span class="pre">Finder.find_module()</span></tt></a> which is equivalent to <tt class="docutils literal"><span class="pre">self.find_loader(fullname)[0]</span></tt>.</p> </dd></dl> <dl class="method"> <dt id="importlib.abc.PathEntryFinder.invalidate_caches"> <tt class="descname">invalidate_caches</tt><big>(</big><big>)</big><a class="headerlink" href="#importlib.abc.PathEntryFinder.invalidate_caches" title="Permalink to this definition">¶</a></dt> <dd><p>An optional method which, when called, should invalidate any internal cache used by the finder. Used by <tt class="xref py py-meth docutils literal"><span class="pre">PathFinder.invalidate_caches()</span></tt> when invalidating the caches of all cached finders.</p> </dd></dl> </dd></dl> <dl class="class"> <dt id="importlib.abc.Loader"> <em class="property">class </em><tt class="descclassname">importlib.abc.</tt><tt class="descname">Loader</tt><a class="headerlink" href="#importlib.abc.Loader" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract base class for a <a class="reference internal" href="../glossary.html#term-loader"><em class="xref std std-term">loader</em></a>. See <span class="target" id="index-9"></span><a class="pep reference external" href="http://www.python.org/dev/peps/pep-0302"><strong>PEP 302</strong></a> for the exact definition for a loader.</p> <dl class="method"> <dt id="importlib.abc.Loader.load_module"> <tt class="descname">load_module</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.abc.Loader.load_module" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract method for loading a module. If the module cannot be loaded, <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><tt class="xref py py-exc docutils literal"><span class="pre">ImportError</span></tt></a> is raised, otherwise the loaded module is returned.</p> <p>If the requested module already exists in <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><tt class="xref py py-data docutils literal"><span class="pre">sys.modules</span></tt></a>, that module should be used and reloaded. Otherwise the loader should create a new module and insert it into <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><tt class="xref py py-data docutils literal"><span class="pre">sys.modules</span></tt></a> before any loading begins, to prevent recursion from the import. If the loader inserted a module and the load fails, it must be removed by the loader from <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><tt class="xref py py-data docutils literal"><span class="pre">sys.modules</span></tt></a>; modules already in <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><tt class="xref py py-data docutils literal"><span class="pre">sys.modules</span></tt></a> before the loader began execution should be left alone. The <a class="reference internal" href="#importlib.util.module_for_loader" title="importlib.util.module_for_loader"><tt class="xref py py-func docutils literal"><span class="pre">importlib.util.module_for_loader()</span></tt></a> decorator handles all of these details.</p> <p>The loader should set several attributes on the module. (Note that some of these attributes can change when a module is reloaded.)</p> <ul> <li><dl class="first docutils"> <dt><tt class="xref py py-attr docutils literal"><span class="pre">__name__</span></tt></dt> <dd><p class="first last">The name of the module.</p> </dd> </dl> </li> <li><dl class="first docutils"> <dt><tt class="xref py py-attr docutils literal"><span class="pre">__file__</span></tt></dt> <dd><p class="first last">The path to where the module data is stored (not set for built-in modules).</p> </dd> </dl> </li> <li><dl class="first docutils"> <dt><tt class="xref py py-attr docutils literal"><span class="pre">__path__</span></tt></dt> <dd><p class="first last">A list of strings specifying the search path within a package. This attribute is not set on modules.</p> </dd> </dl> </li> <li><dl class="first docutils"> <dt><tt class="xref py py-attr docutils literal"><span class="pre">__package__</span></tt></dt> <dd><p class="first last">The parent package for the module/package. If the module is top-level then it has a value of the empty string. The <a class="reference internal" href="#importlib.util.set_package" title="importlib.util.set_package"><tt class="xref py py-func docutils literal"><span class="pre">importlib.util.set_package()</span></tt></a> decorator can handle the details for <tt class="xref py py-attr docutils literal"><span class="pre">__package__</span></tt>.</p> </dd> </dl> </li> <li><dl class="first docutils"> <dt><tt class="xref py py-attr docutils literal"><span class="pre">__loader__</span></tt></dt> <dd><p class="first last">The loader used to load the module. (This is not set by the built-in import machinery, but it should be set whenever a <a class="reference internal" href="../glossary.html#term-loader"><em class="xref std std-term">loader</em></a> is used.)</p> </dd> </dl> </li> </ul> </dd></dl> <dl class="method"> <dt id="importlib.abc.Loader.module_repr"> <tt class="descname">module_repr</tt><big>(</big><em>module</em><big>)</big><a class="headerlink" href="#importlib.abc.Loader.module_repr" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract method which when implemented calculates and returns the given module’s repr, as a string.</p> </dd></dl> </dd></dl> <dl class="class"> <dt id="importlib.abc.ResourceLoader"> <em class="property">class </em><tt class="descclassname">importlib.abc.</tt><tt class="descname">ResourceLoader</tt><a class="headerlink" href="#importlib.abc.ResourceLoader" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract base class for a <a class="reference internal" href="../glossary.html#term-loader"><em class="xref std std-term">loader</em></a> which implements the optional <span class="target" id="index-10"></span><a class="pep reference external" href="http://www.python.org/dev/peps/pep-0302"><strong>PEP 302</strong></a> protocol for loading arbitrary resources from the storage back-end.</p> <dl class="method"> <dt id="importlib.abc.ResourceLoader.get_data"> <tt class="descname">get_data</tt><big>(</big><em>path</em><big>)</big><a class="headerlink" href="#importlib.abc.ResourceLoader.get_data" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract method to return the bytes for the data located at <em>path</em>. Loaders that have a file-like storage back-end that allows storing arbitrary data can implement this abstract method to give direct access to the data stored. <a class="reference internal" href="exceptions.html#IOError" title="IOError"><tt class="xref py py-exc docutils literal"><span class="pre">IOError</span></tt></a> is to be raised if the <em>path</em> cannot be found. The <em>path</em> is expected to be constructed using a module’s <tt class="xref py py-attr docutils literal"><span class="pre">__file__</span></tt> attribute or an item from a package’s <tt class="xref py py-attr docutils literal"><span class="pre">__path__</span></tt>.</p> </dd></dl> </dd></dl> <dl class="class"> <dt id="importlib.abc.InspectLoader"> <em class="property">class </em><tt class="descclassname">importlib.abc.</tt><tt class="descname">InspectLoader</tt><a class="headerlink" href="#importlib.abc.InspectLoader" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract base class for a <a class="reference internal" href="../glossary.html#term-loader"><em class="xref std std-term">loader</em></a> which implements the optional <span class="target" id="index-11"></span><a class="pep reference external" href="http://www.python.org/dev/peps/pep-0302"><strong>PEP 302</strong></a> protocol for loaders that inspect modules.</p> <dl class="method"> <dt id="importlib.abc.InspectLoader.get_code"> <tt class="descname">get_code</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.abc.InspectLoader.get_code" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract method to return the <a class="reference internal" href="code.html#module-code" title="code: Facilities to implement read-eval-print loops."><tt class="xref py py-class docutils literal"><span class="pre">code</span></tt></a> object for a module. <tt class="xref docutils literal"><span class="pre">None</span></tt> is returned if the module does not have a code object (e.g. built-in module). <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><tt class="xref py py-exc docutils literal"><span class="pre">ImportError</span></tt></a> is raised if loader cannot find the requested module.</p> <span class="target" id="index-12"></span></dd></dl> <dl class="method"> <dt id="importlib.abc.InspectLoader.get_source"> <tt class="descname">get_source</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.abc.InspectLoader.get_source" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract method to return the source of a module. It is returned as a text string using <a class="reference internal" href="../glossary.html#term-universal-newlines"><em class="xref std std-term">universal newlines</em></a>, translating all recognized line separators into <tt class="docutils literal"><span class="pre">'\n'</span></tt> characters. Returns <tt class="xref docutils literal"><span class="pre">None</span></tt> if no source is available (e.g. a built-in module). Raises <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><tt class="xref py py-exc docutils literal"><span class="pre">ImportError</span></tt></a> if the loader cannot find the module specified.</p> </dd></dl> <dl class="method"> <dt id="importlib.abc.InspectLoader.is_package"> <tt class="descname">is_package</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.abc.InspectLoader.is_package" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract method to return a true value if the module is a package, a false value otherwise. <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><tt class="xref py py-exc docutils literal"><span class="pre">ImportError</span></tt></a> is raised if the <a class="reference internal" href="../glossary.html#term-loader"><em class="xref std std-term">loader</em></a> cannot find the module.</p> </dd></dl> </dd></dl> <dl class="class"> <dt id="importlib.abc.ExecutionLoader"> <em class="property">class </em><tt class="descclassname">importlib.abc.</tt><tt class="descname">ExecutionLoader</tt><a class="headerlink" href="#importlib.abc.ExecutionLoader" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract base class which inherits from <a class="reference internal" href="#importlib.abc.InspectLoader" title="importlib.abc.InspectLoader"><tt class="xref py py-class docutils literal"><span class="pre">InspectLoader</span></tt></a> that, when implemented, helps a module to be executed as a script. The ABC represents an optional <span class="target" id="index-13"></span><a class="pep reference external" href="http://www.python.org/dev/peps/pep-0302"><strong>PEP 302</strong></a> protocol.</p> <dl class="method"> <dt id="importlib.abc.ExecutionLoader.get_filename"> <tt class="descname">get_filename</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.abc.ExecutionLoader.get_filename" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract method that is to return the value of <tt class="xref py py-attr docutils literal"><span class="pre">__file__</span></tt> for the specified module. If no path is available, <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><tt class="xref py py-exc docutils literal"><span class="pre">ImportError</span></tt></a> is raised.</p> <p>If source code is available, then the method should return the path to the source file, regardless of whether a bytecode was used to load the module.</p> </dd></dl> </dd></dl> <dl class="class"> <dt id="importlib.abc.FileLoader"> <em class="property">class </em><tt class="descclassname">importlib.abc.</tt><tt class="descname">FileLoader</tt><big>(</big><em>fullname</em>, <em>path</em><big>)</big><a class="headerlink" href="#importlib.abc.FileLoader" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract base class which inherits from <a class="reference internal" href="#importlib.abc.ResourceLoader" title="importlib.abc.ResourceLoader"><tt class="xref py py-class docutils literal"><span class="pre">ResourceLoader</span></tt></a> and <a class="reference internal" href="#importlib.abc.ExecutionLoader" title="importlib.abc.ExecutionLoader"><tt class="xref py py-class docutils literal"><span class="pre">ExecutionLoader</span></tt></a>, providing concreate implementations of <a class="reference internal" href="#importlib.abc.ResourceLoader.get_data" title="importlib.abc.ResourceLoader.get_data"><tt class="xref py py-meth docutils literal"><span class="pre">ResourceLoader.get_data()</span></tt></a> and <a class="reference internal" href="#importlib.abc.ExecutionLoader.get_filename" title="importlib.abc.ExecutionLoader.get_filename"><tt class="xref py py-meth docutils literal"><span class="pre">ExecutionLoader.get_filename()</span></tt></a>.</p> <p>The <em>fullname</em> argument is a fully resolved name of the module the loader is to handle. The <em>path</em> argument is the path to the file for the module.</p> <p class="versionadded"> <span class="versionmodified">New in version 3.3.</span> </p> <dl class="attribute"> <dt id="importlib.abc.FileLoader.name"> <tt class="descname">name</tt><a class="headerlink" href="#importlib.abc.FileLoader.name" title="Permalink to this definition">¶</a></dt> <dd><p>The name of the module the loader can handle.</p> </dd></dl> <dl class="attribute"> <dt id="importlib.abc.FileLoader.path"> <tt class="descname">path</tt><a class="headerlink" href="#importlib.abc.FileLoader.path" title="Permalink to this definition">¶</a></dt> <dd><p>Path to the file of the module.</p> </dd></dl> <dl class="method"> <dt id="importlib.abc.FileLoader.load_module"> <tt class="descname">load_module</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.abc.FileLoader.load_module" title="Permalink to this definition">¶</a></dt> <dd><p>Calls super’s <tt class="docutils literal"><span class="pre">load_module()</span></tt>.</p> </dd></dl> <dl class="method"> <dt id="importlib.abc.FileLoader.get_filename"> <tt class="descname">get_filename</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.abc.FileLoader.get_filename" title="Permalink to this definition">¶</a></dt> <dd><p>Returns <a class="reference internal" href="#importlib.abc.FileLoader.path" title="importlib.abc.FileLoader.path"><tt class="xref py py-attr docutils literal"><span class="pre">path</span></tt></a>.</p> </dd></dl> <dl class="method"> <dt id="importlib.abc.FileLoader.get_data"> <tt class="descname">get_data</tt><big>(</big><em>path</em><big>)</big><a class="headerlink" href="#importlib.abc.FileLoader.get_data" title="Permalink to this definition">¶</a></dt> <dd><p>Returns the open, binary file for <em>path</em>.</p> </dd></dl> </dd></dl> <dl class="class"> <dt id="importlib.abc.SourceLoader"> <em class="property">class </em><tt class="descclassname">importlib.abc.</tt><tt class="descname">SourceLoader</tt><a class="headerlink" href="#importlib.abc.SourceLoader" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract base class for implementing source (and optionally bytecode) file loading. The class inherits from both <a class="reference internal" href="#importlib.abc.ResourceLoader" title="importlib.abc.ResourceLoader"><tt class="xref py py-class docutils literal"><span class="pre">ResourceLoader</span></tt></a> and <a class="reference internal" href="#importlib.abc.ExecutionLoader" title="importlib.abc.ExecutionLoader"><tt class="xref py py-class docutils literal"><span class="pre">ExecutionLoader</span></tt></a>, requiring the implementation of:</p> <ul> <li><p class="first"><a class="reference internal" href="#importlib.abc.ResourceLoader.get_data" title="importlib.abc.ResourceLoader.get_data"><tt class="xref py py-meth docutils literal"><span class="pre">ResourceLoader.get_data()</span></tt></a></p> </li> <li><dl class="first docutils"> <dt><a class="reference internal" href="#importlib.abc.ExecutionLoader.get_filename" title="importlib.abc.ExecutionLoader.get_filename"><tt class="xref py py-meth docutils literal"><span class="pre">ExecutionLoader.get_filename()</span></tt></a></dt> <dd><p class="first last">Should only return the path to the source file; sourceless loading is not supported.</p> </dd> </dl> </li> </ul> <p>The abstract methods defined by this class are to add optional bytecode file support. Not implementing these optional methods causes the loader to only work with source code. Implementing the methods allows the loader to work with source <em>and</em> bytecode files; it does not allow for <em>sourceless</em> loading where only bytecode is provided. Bytecode files are an optimization to speed up loading by removing the parsing step of Python’s compiler, and so no bytecode-specific API is exposed.</p> <dl class="method"> <dt id="importlib.abc.SourceLoader.path_stats"> <tt class="descname">path_stats</tt><big>(</big><em>path</em><big>)</big><a class="headerlink" href="#importlib.abc.SourceLoader.path_stats" title="Permalink to this definition">¶</a></dt> <dd><p>Optional abstract method which returns a <a class="reference internal" href="stdtypes.html#dict" title="dict"><tt class="xref py py-class docutils literal"><span class="pre">dict</span></tt></a> containing metadata about the specifed path. Supported dictionary keys are:</p> <ul class="simple"> <li><tt class="docutils literal"><span class="pre">'mtime'</span></tt> (mandatory): an integer or floating-point number representing the modification time of the source code;</li> <li><tt class="docutils literal"><span class="pre">'size'</span></tt> (optional): the size in bytes of the source code.</li> </ul> <p>Any other keys in the dictionary are ignored, to allow for future extensions.</p> <p class="versionadded"> <span class="versionmodified">New in version 3.3.</span> </p> </dd></dl> <dl class="method"> <dt id="importlib.abc.SourceLoader.path_mtime"> <tt class="descname">path_mtime</tt><big>(</big><em>path</em><big>)</big><a class="headerlink" href="#importlib.abc.SourceLoader.path_mtime" title="Permalink to this definition">¶</a></dt> <dd><p>Optional abstract method which returns the modification time for the specified path.</p> <p class="deprecated"> <span class="versionmodified">Deprecated since version 3.3:</span> This method is deprecated in favour of <a class="reference internal" href="#importlib.abc.SourceLoader.path_stats" title="importlib.abc.SourceLoader.path_stats"><tt class="xref py py-meth docutils literal"><span class="pre">path_stats()</span></tt></a>. You don’t have to implement it, but it is still available for compatibility purposes.</p> </dd></dl> <dl class="method"> <dt id="importlib.abc.SourceLoader.set_data"> <tt class="descname">set_data</tt><big>(</big><em>path</em>, <em>data</em><big>)</big><a class="headerlink" href="#importlib.abc.SourceLoader.set_data" title="Permalink to this definition">¶</a></dt> <dd><p>Optional abstract method which writes the specified bytes to a file path. Any intermediate directories which do not exist are to be created automatically.</p> <p>When writing to the path fails because the path is read-only (<a class="reference internal" href="errno.html#errno.EACCES" title="errno.EACCES"><tt class="xref py py-attr docutils literal"><span class="pre">errno.EACCES</span></tt></a>), do not propagate the exception.</p> </dd></dl> <dl class="method"> <dt id="importlib.abc.SourceLoader.get_code"> <tt class="descname">get_code</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.abc.SourceLoader.get_code" title="Permalink to this definition">¶</a></dt> <dd><p>Concrete implementation of <a class="reference internal" href="#importlib.abc.InspectLoader.get_code" title="importlib.abc.InspectLoader.get_code"><tt class="xref py py-meth docutils literal"><span class="pre">InspectLoader.get_code()</span></tt></a>.</p> </dd></dl> <dl class="method"> <dt id="importlib.abc.SourceLoader.load_module"> <tt class="descname">load_module</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.abc.SourceLoader.load_module" title="Permalink to this definition">¶</a></dt> <dd><p>Concrete implementation of <a class="reference internal" href="#importlib.abc.Loader.load_module" title="importlib.abc.Loader.load_module"><tt class="xref py py-meth docutils literal"><span class="pre">Loader.load_module()</span></tt></a>.</p> </dd></dl> <dl class="method"> <dt id="importlib.abc.SourceLoader.get_source"> <tt class="descname">get_source</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.abc.SourceLoader.get_source" title="Permalink to this definition">¶</a></dt> <dd><p>Concrete implementation of <a class="reference internal" href="#importlib.abc.InspectLoader.get_source" title="importlib.abc.InspectLoader.get_source"><tt class="xref py py-meth docutils literal"><span class="pre">InspectLoader.get_source()</span></tt></a>.</p> </dd></dl> <dl class="method"> <dt id="importlib.abc.SourceLoader.is_package"> <tt class="descname">is_package</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.abc.SourceLoader.is_package" title="Permalink to this definition">¶</a></dt> <dd><p>Concrete implementation of <a class="reference internal" href="#importlib.abc.InspectLoader.is_package" title="importlib.abc.InspectLoader.is_package"><tt class="xref py py-meth docutils literal"><span class="pre">InspectLoader.is_package()</span></tt></a>. A module is determined to be a package if its file path (as provided by <a class="reference internal" href="#importlib.abc.ExecutionLoader.get_filename" title="importlib.abc.ExecutionLoader.get_filename"><tt class="xref py py-meth docutils literal"><span class="pre">ExecutionLoader.get_filename()</span></tt></a>) is a file named <tt class="docutils literal"><span class="pre">__init__</span></tt> when the file extension is removed <strong>and</strong> the module name itself does not end in <tt class="docutils literal"><span class="pre">__init__</span></tt>.</p> </dd></dl> </dd></dl> <dl class="class"> <dt id="importlib.abc.PyLoader"> <em class="property">class </em><tt class="descclassname">importlib.abc.</tt><tt class="descname">PyLoader</tt><a class="headerlink" href="#importlib.abc.PyLoader" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract base class inheriting from <a class="reference internal" href="#importlib.abc.ExecutionLoader" title="importlib.abc.ExecutionLoader"><tt class="xref py py-class docutils literal"><span class="pre">ExecutionLoader</span></tt></a> and <a class="reference internal" href="#importlib.abc.ResourceLoader" title="importlib.abc.ResourceLoader"><tt class="xref py py-class docutils literal"><span class="pre">ResourceLoader</span></tt></a> designed to ease the loading of Python source modules (bytecode is not handled; see <a class="reference internal" href="#importlib.abc.SourceLoader" title="importlib.abc.SourceLoader"><tt class="xref py py-class docutils literal"><span class="pre">SourceLoader</span></tt></a> for a source/bytecode ABC). A subclass implementing this ABC will only need to worry about exposing how the source code is stored; all other details for loading Python source code will be handled by the concrete implementations of key methods.</p> <p class="deprecated"> <span class="versionmodified">Deprecated since version 3.2:</span> This class has been deprecated in favor of <a class="reference internal" href="#importlib.abc.SourceLoader" title="importlib.abc.SourceLoader"><tt class="xref py py-class docutils literal"><span class="pre">SourceLoader</span></tt></a> and is slated for removal in Python 3.4. See below for how to create a subclass that is compatible with Python 3.1 onwards.</p> <p>If compatibility with Python 3.1 is required, then use the following idiom to implement a subclass that will work with Python 3.1 onwards (make sure to implement <a class="reference internal" href="#importlib.abc.ExecutionLoader.get_filename" title="importlib.abc.ExecutionLoader.get_filename"><tt class="xref py py-meth docutils literal"><span class="pre">ExecutionLoader.get_filename()</span></tt></a>):</p> <div class="highlight-python3"><div class="highlight"><pre><span class="k">try</span><span class="p">:</span> <span class="kn">from</span> <span class="nn">importlib.abc</span> <span class="k">import</span> <span class="n">SourceLoader</span> <span class="k">except</span> <span class="ne">ImportError</span><span class="p">:</span> <span class="kn">from</span> <span class="nn">importlib.abc</span> <span class="k">import</span> <span class="n">PyLoader</span> <span class="k">as</span> <span class="n">SourceLoader</span> <span class="k">class</span> <span class="nc">CustomLoader</span><span class="p">(</span><span class="n">SourceLoader</span><span class="p">):</span> <span class="k">def</span> <span class="nf">get_filename</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">fullname</span><span class="p">):</span> <span class="sd">"""Return the path to the source file."""</span> <span class="c"># Implement ...</span> <span class="k">def</span> <span class="nf">source_path</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">fullname</span><span class="p">):</span> <span class="sd">"""Implement source_path in terms of get_filename."""</span> <span class="k">try</span><span class="p">:</span> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">get_filename</span><span class="p">(</span><span class="n">fullname</span><span class="p">)</span> <span class="k">except</span> <span class="ne">ImportError</span><span class="p">:</span> <span class="k">return</span> <span class="k">None</span> <span class="k">def</span> <span class="nf">is_package</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">fullname</span><span class="p">):</span> <span class="sd">"""Implement is_package by looking for an __init__ file</span> <span class="sd"> name as returned by get_filename."""</span> <span class="n">filename</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">basename</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">get_filename</span><span class="p">(</span><span class="n">fullname</span><span class="p">))</span> <span class="k">return</span> <span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">splitext</span><span class="p">(</span><span class="n">filename</span><span class="p">)[</span><span class="mi">0</span><span class="p">]</span> <span class="o">==</span> <span class="s">'__init__'</span> </pre></div> </div> <dl class="method"> <dt id="importlib.abc.PyLoader.source_path"> <tt class="descname">source_path</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.abc.PyLoader.source_path" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract method that returns the path to the source code for a module. Should return <tt class="xref docutils literal"><span class="pre">None</span></tt> if there is no source code. Raises <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><tt class="xref py py-exc docutils literal"><span class="pre">ImportError</span></tt></a> if the loader knows it cannot handle the module.</p> </dd></dl> <dl class="method"> <dt id="importlib.abc.PyLoader.get_filename"> <tt class="descname">get_filename</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.abc.PyLoader.get_filename" title="Permalink to this definition">¶</a></dt> <dd><p>A concrete implementation of <a class="reference internal" href="#importlib.abc.ExecutionLoader.get_filename" title="importlib.abc.ExecutionLoader.get_filename"><tt class="xref py py-meth docutils literal"><span class="pre">importlib.abc.ExecutionLoader.get_filename()</span></tt></a> that relies on <a class="reference internal" href="#importlib.abc.PyLoader.source_path" title="importlib.abc.PyLoader.source_path"><tt class="xref py py-meth docutils literal"><span class="pre">source_path()</span></tt></a>. If <a class="reference internal" href="#importlib.abc.PyLoader.source_path" title="importlib.abc.PyLoader.source_path"><tt class="xref py py-meth docutils literal"><span class="pre">source_path()</span></tt></a> returns <tt class="xref docutils literal"><span class="pre">None</span></tt>, then <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><tt class="xref py py-exc docutils literal"><span class="pre">ImportError</span></tt></a> is raised.</p> </dd></dl> <dl class="method"> <dt id="importlib.abc.PyLoader.load_module"> <tt class="descname">load_module</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.abc.PyLoader.load_module" title="Permalink to this definition">¶</a></dt> <dd><p>A concrete implementation of <a class="reference internal" href="#importlib.abc.Loader.load_module" title="importlib.abc.Loader.load_module"><tt class="xref py py-meth docutils literal"><span class="pre">importlib.abc.Loader.load_module()</span></tt></a> that loads Python source code. All needed information comes from the abstract methods required by this ABC. The only pertinent assumption made by this method is that when loading a package <tt class="xref py py-attr docutils literal"><span class="pre">__path__</span></tt> is set to <tt class="docutils literal"><span class="pre">[os.path.dirname(__file__)]</span></tt>.</p> </dd></dl> <dl class="method"> <dt id="importlib.abc.PyLoader.get_code"> <tt class="descname">get_code</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.abc.PyLoader.get_code" title="Permalink to this definition">¶</a></dt> <dd><p>A concrete implementation of <a class="reference internal" href="#importlib.abc.InspectLoader.get_code" title="importlib.abc.InspectLoader.get_code"><tt class="xref py py-meth docutils literal"><span class="pre">importlib.abc.InspectLoader.get_code()</span></tt></a> that creates code objects from Python source code, by requesting the source code (using <a class="reference internal" href="#importlib.abc.PyLoader.source_path" title="importlib.abc.PyLoader.source_path"><tt class="xref py py-meth docutils literal"><span class="pre">source_path()</span></tt></a> and <tt class="xref py py-meth docutils literal"><span class="pre">get_data()</span></tt>) and compiling it with the built-in <a class="reference internal" href="functions.html#compile" title="compile"><tt class="xref py py-func docutils literal"><span class="pre">compile()</span></tt></a> function.</p> </dd></dl> <dl class="method"> <dt id="importlib.abc.PyLoader.get_source"> <tt class="descname">get_source</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.abc.PyLoader.get_source" title="Permalink to this definition">¶</a></dt> <dd><p>A concrete implementation of <a class="reference internal" href="#importlib.abc.InspectLoader.get_source" title="importlib.abc.InspectLoader.get_source"><tt class="xref py py-meth docutils literal"><span class="pre">importlib.abc.InspectLoader.get_source()</span></tt></a>. Uses <a class="reference internal" href="#importlib.abc.ResourceLoader.get_data" title="importlib.abc.ResourceLoader.get_data"><tt class="xref py py-meth docutils literal"><span class="pre">importlib.abc.ResourceLoader.get_data()</span></tt></a> and <a class="reference internal" href="#importlib.abc.PyLoader.source_path" title="importlib.abc.PyLoader.source_path"><tt class="xref py py-meth docutils literal"><span class="pre">source_path()</span></tt></a> to get the source code. It tries to guess the source encoding using <a class="reference internal" href="tokenize.html#tokenize.detect_encoding" title="tokenize.detect_encoding"><tt class="xref py py-func docutils literal"><span class="pre">tokenize.detect_encoding()</span></tt></a>.</p> </dd></dl> </dd></dl> <dl class="class"> <dt id="importlib.abc.PyPycLoader"> <em class="property">class </em><tt class="descclassname">importlib.abc.</tt><tt class="descname">PyPycLoader</tt><a class="headerlink" href="#importlib.abc.PyPycLoader" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract base class inheriting from <a class="reference internal" href="#importlib.abc.PyLoader" title="importlib.abc.PyLoader"><tt class="xref py py-class docutils literal"><span class="pre">PyLoader</span></tt></a>. This ABC is meant to help in creating loaders that support both Python source and bytecode.</p> <p class="deprecated"> <span class="versionmodified">Deprecated since version 3.2:</span> This class has been deprecated in favor of <a class="reference internal" href="#importlib.abc.SourceLoader" title="importlib.abc.SourceLoader"><tt class="xref py py-class docutils literal"><span class="pre">SourceLoader</span></tt></a> and to properly support <span class="target" id="index-14"></span><a class="pep reference external" href="http://www.python.org/dev/peps/pep-3147"><strong>PEP 3147</strong></a>. If compatibility is required with Python 3.1, implement both <a class="reference internal" href="#importlib.abc.SourceLoader" title="importlib.abc.SourceLoader"><tt class="xref py py-class docutils literal"><span class="pre">SourceLoader</span></tt></a> and <a class="reference internal" href="#importlib.abc.PyLoader" title="importlib.abc.PyLoader"><tt class="xref py py-class docutils literal"><span class="pre">PyLoader</span></tt></a>; instructions on how to do so are included in the documentation for <a class="reference internal" href="#importlib.abc.PyLoader" title="importlib.abc.PyLoader"><tt class="xref py py-class docutils literal"><span class="pre">PyLoader</span></tt></a>. Do note that this solution will not support sourceless/bytecode-only loading; only source <em>and</em> bytecode loading.</p> <p class="versionchanged"> <span class="versionmodified">Changed in version 3.3:</span> Updated to parse (but not use) the new source size field in bytecode files when reading and to write out the field properly when writing.</p> <dl class="method"> <dt id="importlib.abc.PyPycLoader.source_mtime"> <tt class="descname">source_mtime</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.abc.PyPycLoader.source_mtime" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract method which returns the modification time for the source code of the specified module. The modification time should be an integer. If there is no source code, return <tt class="xref docutils literal"><span class="pre">None</span></tt>. If the module cannot be found then <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><tt class="xref py py-exc docutils literal"><span class="pre">ImportError</span></tt></a> is raised.</p> </dd></dl> <dl class="method"> <dt id="importlib.abc.PyPycLoader.bytecode_path"> <tt class="descname">bytecode_path</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.abc.PyPycLoader.bytecode_path" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract method which returns the path to the bytecode for the specified module, if it exists. It returns <tt class="xref docutils literal"><span class="pre">None</span></tt> if no bytecode exists (yet). Raises <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><tt class="xref py py-exc docutils literal"><span class="pre">ImportError</span></tt></a> if the loader knows it cannot handle the module.</p> </dd></dl> <dl class="method"> <dt id="importlib.abc.PyPycLoader.get_filename"> <tt class="descname">get_filename</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.abc.PyPycLoader.get_filename" title="Permalink to this definition">¶</a></dt> <dd><p>A concrete implementation of <a class="reference internal" href="#importlib.abc.ExecutionLoader.get_filename" title="importlib.abc.ExecutionLoader.get_filename"><tt class="xref py py-meth docutils literal"><span class="pre">ExecutionLoader.get_filename()</span></tt></a> that relies on <a class="reference internal" href="#importlib.abc.PyLoader.source_path" title="importlib.abc.PyLoader.source_path"><tt class="xref py py-meth docutils literal"><span class="pre">PyLoader.source_path()</span></tt></a> and <a class="reference internal" href="#importlib.abc.PyPycLoader.bytecode_path" title="importlib.abc.PyPycLoader.bytecode_path"><tt class="xref py py-meth docutils literal"><span class="pre">bytecode_path()</span></tt></a>. If <tt class="xref py py-meth docutils literal"><span class="pre">source_path()</span></tt> returns a path, then that value is returned. Else if <a class="reference internal" href="#importlib.abc.PyPycLoader.bytecode_path" title="importlib.abc.PyPycLoader.bytecode_path"><tt class="xref py py-meth docutils literal"><span class="pre">bytecode_path()</span></tt></a> returns a path, that path will be returned. If a path is not available from both methods, <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><tt class="xref py py-exc docutils literal"><span class="pre">ImportError</span></tt></a> is raised.</p> </dd></dl> <dl class="method"> <dt id="importlib.abc.PyPycLoader.write_bytecode"> <tt class="descname">write_bytecode</tt><big>(</big><em>fullname</em>, <em>bytecode</em><big>)</big><a class="headerlink" href="#importlib.abc.PyPycLoader.write_bytecode" title="Permalink to this definition">¶</a></dt> <dd><p>An abstract method which has the loader write <em>bytecode</em> for future use. If the bytecode is written, return <tt class="xref docutils literal"><span class="pre">True</span></tt>. Return <tt class="xref docutils literal"><span class="pre">False</span></tt> if the bytecode could not be written. This method should not be called if <a class="reference internal" href="sys.html#sys.dont_write_bytecode" title="sys.dont_write_bytecode"><tt class="xref py py-data docutils literal"><span class="pre">sys.dont_write_bytecode</span></tt></a> is true. The <em>bytecode</em> argument should be a bytes string or bytes array.</p> </dd></dl> </dd></dl> </div> <div class="section" id="module-importlib.machinery"> <span id="importlib-machinery-importers-and-path-hooks"></span><h2>30.6.4. <a class="reference internal" href="#module-importlib.machinery" title="importlib.machinery: Importers and path hooks"><tt class="xref py py-mod docutils literal"><span class="pre">importlib.machinery</span></tt></a> – Importers and path hooks<a class="headerlink" href="#module-importlib.machinery" title="Permalink to this headline">¶</a></h2> <p>This module contains the various objects that help <a class="reference internal" href="../reference/simple_stmts.html#import"><tt class="xref std std-keyword docutils literal"><span class="pre">import</span></tt></a> find and load modules.</p> <dl class="attribute"> <dt id="importlib.machinery.SOURCE_SUFFIXES"> <tt class="descclassname">importlib.machinery.</tt><tt class="descname">SOURCE_SUFFIXES</tt><a class="headerlink" href="#importlib.machinery.SOURCE_SUFFIXES" title="Permalink to this definition">¶</a></dt> <dd><p>A list of strings representing the recognized file suffixes for source modules.</p> <p class="versionadded"> <span class="versionmodified">New in version 3.3.</span> </p> </dd></dl> <dl class="attribute"> <dt id="importlib.machinery.DEBUG_BYTECODE_SUFFIXES"> <tt class="descclassname">importlib.machinery.</tt><tt class="descname">DEBUG_BYTECODE_SUFFIXES</tt><a class="headerlink" href="#importlib.machinery.DEBUG_BYTECODE_SUFFIXES" title="Permalink to this definition">¶</a></dt> <dd><p>A list of strings representing the file suffixes for non-optimized bytecode modules.</p> <p class="versionadded"> <span class="versionmodified">New in version 3.3.</span> </p> </dd></dl> <dl class="attribute"> <dt id="importlib.machinery.OPTIMIZED_BYTECODE_SUFFIXES"> <tt class="descclassname">importlib.machinery.</tt><tt class="descname">OPTIMIZED_BYTECODE_SUFFIXES</tt><a class="headerlink" href="#importlib.machinery.OPTIMIZED_BYTECODE_SUFFIXES" title="Permalink to this definition">¶</a></dt> <dd><p>A list of strings representing the file suffixes for optimized bytecode modules.</p> <p class="versionadded"> <span class="versionmodified">New in version 3.3.</span> </p> </dd></dl> <dl class="attribute"> <dt id="importlib.machinery.BYTECODE_SUFFIXES"> <tt class="descclassname">importlib.machinery.</tt><tt class="descname">BYTECODE_SUFFIXES</tt><a class="headerlink" href="#importlib.machinery.BYTECODE_SUFFIXES" title="Permalink to this definition">¶</a></dt> <dd><p>A list of strings representing the recognized file suffixes for bytecode modules. Set to either <a class="reference internal" href="#importlib.machinery.DEBUG_BYTECODE_SUFFIXES" title="importlib.machinery.DEBUG_BYTECODE_SUFFIXES"><tt class="xref py py-attr docutils literal"><span class="pre">DEBUG_BYTECODE_SUFFIXES</span></tt></a> or <a class="reference internal" href="#importlib.machinery.OPTIMIZED_BYTECODE_SUFFIXES" title="importlib.machinery.OPTIMIZED_BYTECODE_SUFFIXES"><tt class="xref py py-attr docutils literal"><span class="pre">OPTIMIZED_BYTECODE_SUFFIXES</span></tt></a> based on whether <tt class="docutils literal"><span class="pre">__debug__</span></tt> is true.</p> <p class="versionadded"> <span class="versionmodified">New in version 3.3.</span> </p> </dd></dl> <dl class="attribute"> <dt id="importlib.machinery.EXTENSION_SUFFIXES"> <tt class="descclassname">importlib.machinery.</tt><tt class="descname">EXTENSION_SUFFIXES</tt><a class="headerlink" href="#importlib.machinery.EXTENSION_SUFFIXES" title="Permalink to this definition">¶</a></dt> <dd><p>A list of strings representing the recognized file suffixes for extension modules.</p> <p class="versionadded"> <span class="versionmodified">New in version 3.3.</span> </p> </dd></dl> <dl class="function"> <dt id="importlib.machinery.all_suffixes"> <tt class="descclassname">importlib.machinery.</tt><tt class="descname">all_suffixes</tt><big>(</big><big>)</big><a class="headerlink" href="#importlib.machinery.all_suffixes" title="Permalink to this definition">¶</a></dt> <dd><p>Returns a combined list of strings representing all file suffixes for modules recognized by the standard import machinery. This is a helper for code which simply needs to know if a filesystem path potentially refers to a module without needing any details on the kind of module (for example, <a class="reference internal" href="inspect.html#inspect.getmodulename" title="inspect.getmodulename"><tt class="xref py py-func docutils literal"><span class="pre">inspect.getmodulename()</span></tt></a>)</p> <p class="versionadded"> <span class="versionmodified">New in version 3.3.</span> </p> </dd></dl> <dl class="class"> <dt id="importlib.machinery.BuiltinImporter"> <em class="property">class </em><tt class="descclassname">importlib.machinery.</tt><tt class="descname">BuiltinImporter</tt><a class="headerlink" href="#importlib.machinery.BuiltinImporter" title="Permalink to this definition">¶</a></dt> <dd><p>An <a class="reference internal" href="../glossary.html#term-importer"><em class="xref std std-term">importer</em></a> for built-in modules. All known built-in modules are listed in <a class="reference internal" href="sys.html#sys.builtin_module_names" title="sys.builtin_module_names"><tt class="xref py py-data docutils literal"><span class="pre">sys.builtin_module_names</span></tt></a>. This class implements the <a class="reference internal" href="#importlib.abc.MetaPathFinder" title="importlib.abc.MetaPathFinder"><tt class="xref py py-class docutils literal"><span class="pre">importlib.abc.MetaPathFinder</span></tt></a> and <a class="reference internal" href="#importlib.abc.InspectLoader" title="importlib.abc.InspectLoader"><tt class="xref py py-class docutils literal"><span class="pre">importlib.abc.InspectLoader</span></tt></a> ABCs.</p> <p>Only class methods are defined by this class to alleviate the need for instantiation.</p> </dd></dl> <dl class="class"> <dt id="importlib.machinery.FrozenImporter"> <em class="property">class </em><tt class="descclassname">importlib.machinery.</tt><tt class="descname">FrozenImporter</tt><a class="headerlink" href="#importlib.machinery.FrozenImporter" title="Permalink to this definition">¶</a></dt> <dd><p>An <a class="reference internal" href="../glossary.html#term-importer"><em class="xref std std-term">importer</em></a> for frozen modules. This class implements the <a class="reference internal" href="#importlib.abc.MetaPathFinder" title="importlib.abc.MetaPathFinder"><tt class="xref py py-class docutils literal"><span class="pre">importlib.abc.MetaPathFinder</span></tt></a> and <a class="reference internal" href="#importlib.abc.InspectLoader" title="importlib.abc.InspectLoader"><tt class="xref py py-class docutils literal"><span class="pre">importlib.abc.InspectLoader</span></tt></a> ABCs.</p> <p>Only class methods are defined by this class to alleviate the need for instantiation.</p> </dd></dl> <dl class="class"> <dt id="importlib.machinery.WindowsRegistryFinder"> <em class="property">class </em><tt class="descclassname">importlib.machinery.</tt><tt class="descname">WindowsRegistryFinder</tt><a class="headerlink" href="#importlib.machinery.WindowsRegistryFinder" title="Permalink to this definition">¶</a></dt> <dd><p><a class="reference internal" href="../glossary.html#term-finder"><em class="xref std std-term">Finder</em></a> for modules declared in the Windows registry. This class implements the <a class="reference internal" href="#importlib.abc.Finder" title="importlib.abc.Finder"><tt class="xref py py-class docutils literal"><span class="pre">importlib.abc.Finder</span></tt></a> ABC.</p> <p>Only class methods are defined by this class to alleviate the need for instantiation.</p> <p class="versionadded"> <span class="versionmodified">New in version 3.3.</span> </p> </dd></dl> <dl class="class"> <dt id="importlib.machinery.PathFinder"> <em class="property">class </em><tt class="descclassname">importlib.machinery.</tt><tt class="descname">PathFinder</tt><a class="headerlink" href="#importlib.machinery.PathFinder" title="Permalink to this definition">¶</a></dt> <dd><p>A <a class="reference internal" href="../glossary.html#term-finder"><em class="xref std std-term">Finder</em></a> for <a class="reference internal" href="sys.html#sys.path" title="sys.path"><tt class="xref py py-data docutils literal"><span class="pre">sys.path</span></tt></a> and package <tt class="docutils literal"><span class="pre">__path__</span></tt> attributes. This class implements the <a class="reference internal" href="#importlib.abc.MetaPathFinder" title="importlib.abc.MetaPathFinder"><tt class="xref py py-class docutils literal"><span class="pre">importlib.abc.MetaPathFinder</span></tt></a> ABC.</p> <p>Only class methods are defined by this class to alleviate the need for instantiation.</p> <dl class="classmethod"> <dt id="importlib.machinery.PathFinder.find_module"> <em class="property">classmethod </em><tt class="descname">find_module</tt><big>(</big><em>fullname</em>, <em>path=None</em><big>)</big><a class="headerlink" href="#importlib.machinery.PathFinder.find_module" title="Permalink to this definition">¶</a></dt> <dd><p>Class method that attempts to find a <a class="reference internal" href="../glossary.html#term-loader"><em class="xref std std-term">loader</em></a> for the module specified by <em>fullname</em> on <a class="reference internal" href="sys.html#sys.path" title="sys.path"><tt class="xref py py-data docutils literal"><span class="pre">sys.path</span></tt></a> or, if defined, on <em>path</em>. For each path entry that is searched, <a class="reference internal" href="sys.html#sys.path_importer_cache" title="sys.path_importer_cache"><tt class="xref py py-data docutils literal"><span class="pre">sys.path_importer_cache</span></tt></a> is checked. If a non-false object is found then it is used as the <a class="reference internal" href="../glossary.html#term-finder"><em class="xref std std-term">finder</em></a> to look for the module being searched for. If no entry is found in <a class="reference internal" href="sys.html#sys.path_importer_cache" title="sys.path_importer_cache"><tt class="xref py py-data docutils literal"><span class="pre">sys.path_importer_cache</span></tt></a>, then <a class="reference internal" href="sys.html#sys.path_hooks" title="sys.path_hooks"><tt class="xref py py-data docutils literal"><span class="pre">sys.path_hooks</span></tt></a> is searched for a finder for the path entry and, if found, is stored in <a class="reference internal" href="sys.html#sys.path_importer_cache" title="sys.path_importer_cache"><tt class="xref py py-data docutils literal"><span class="pre">sys.path_importer_cache</span></tt></a> along with being queried about the module. If no finder is ever found then <tt class="xref docutils literal"><span class="pre">None</span></tt> is both stored in the cache and returned.</p> </dd></dl> <dl class="classmethod"> <dt id="importlib.machinery.PathFinder.invalidate_caches"> <em class="property">classmethod </em><tt class="descname">invalidate_caches</tt><big>(</big><big>)</big><a class="headerlink" href="#importlib.machinery.PathFinder.invalidate_caches" title="Permalink to this definition">¶</a></dt> <dd><p>Calls <a class="reference internal" href="#importlib.abc.PathEntryFinder.invalidate_caches" title="importlib.abc.PathEntryFinder.invalidate_caches"><tt class="xref py py-meth docutils literal"><span class="pre">importlib.abc.PathEntryFinder.invalidate_caches()</span></tt></a> on all finders stored in <a class="reference internal" href="sys.html#sys.path_importer_cache" title="sys.path_importer_cache"><tt class="xref py py-attr docutils literal"><span class="pre">sys.path_importer_cache</span></tt></a>.</p> </dd></dl> </dd></dl> <dl class="class"> <dt id="importlib.machinery.FileFinder"> <em class="property">class </em><tt class="descclassname">importlib.machinery.</tt><tt class="descname">FileFinder</tt><big>(</big><em>path</em>, <em>*loader_details</em><big>)</big><a class="headerlink" href="#importlib.machinery.FileFinder" title="Permalink to this definition">¶</a></dt> <dd><p>A concrete implementation of <a class="reference internal" href="#importlib.abc.PathEntryFinder" title="importlib.abc.PathEntryFinder"><tt class="xref py py-class docutils literal"><span class="pre">importlib.abc.PathEntryFinder</span></tt></a> which caches results from the file system.</p> <p>The <em>path</em> argument is the directory for which the finder is in charge of searching.</p> <p>The <em>loader_details</em> argument is a variable number of 2-item tuples each containing a loader and a sequence of file suffixes the loader recognizes.</p> <p>The finder will cache the directory contents as necessary, making stat calls for each module search to verify the cache is not outdated. Because cache staleness relies upon the granularity of the operating system’s state information of the file system, there is a potential race condition of searching for a module, creating a new file, and then searching for the module the new file represents. If the operations happen fast enough to fit within the granularity of stat calls, then the module search will fail. To prevent this from happening, when you create a module dynamically, make sure to call <a class="reference internal" href="#importlib.invalidate_caches" title="importlib.invalidate_caches"><tt class="xref py py-func docutils literal"><span class="pre">importlib.invalidate_caches()</span></tt></a>.</p> <p class="versionadded"> <span class="versionmodified">New in version 3.3.</span> </p> <dl class="attribute"> <dt id="importlib.machinery.FileFinder.path"> <tt class="descname">path</tt><a class="headerlink" href="#importlib.machinery.FileFinder.path" title="Permalink to this definition">¶</a></dt> <dd><p>The path the finder will search in.</p> </dd></dl> <dl class="method"> <dt id="importlib.machinery.FileFinder.find_module"> <tt class="descname">find_module</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.machinery.FileFinder.find_module" title="Permalink to this definition">¶</a></dt> <dd><p>Attempt to find the loader to handle <em>fullname</em> within <a class="reference internal" href="#importlib.machinery.FileFinder.path" title="importlib.machinery.FileFinder.path"><tt class="xref py py-attr docutils literal"><span class="pre">path</span></tt></a>.</p> </dd></dl> <dl class="method"> <dt id="importlib.machinery.FileFinder.invalidate_caches"> <tt class="descname">invalidate_caches</tt><big>(</big><big>)</big><a class="headerlink" href="#importlib.machinery.FileFinder.invalidate_caches" title="Permalink to this definition">¶</a></dt> <dd><p>Clear out the internal cache.</p> </dd></dl> <dl class="classmethod"> <dt id="importlib.machinery.FileFinder.path_hook"> <em class="property">classmethod </em><tt class="descname">path_hook</tt><big>(</big><em>*loader_details</em><big>)</big><a class="headerlink" href="#importlib.machinery.FileFinder.path_hook" title="Permalink to this definition">¶</a></dt> <dd><p>A class method which returns a closure for use on <a class="reference internal" href="sys.html#sys.path_hooks" title="sys.path_hooks"><tt class="xref py py-attr docutils literal"><span class="pre">sys.path_hooks</span></tt></a>. An instance of <a class="reference internal" href="#importlib.machinery.FileFinder" title="importlib.machinery.FileFinder"><tt class="xref py py-class docutils literal"><span class="pre">FileFinder</span></tt></a> is returned by the closure using the path argument given to the closure directly and <em>loader_details</em> indirectly.</p> <p>If the argument to the closure is not an existing directory, <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><tt class="xref py py-exc docutils literal"><span class="pre">ImportError</span></tt></a> is raised.</p> </dd></dl> </dd></dl> <dl class="class"> <dt id="importlib.machinery.SourceFileLoader"> <em class="property">class </em><tt class="descclassname">importlib.machinery.</tt><tt class="descname">SourceFileLoader</tt><big>(</big><em>fullname</em>, <em>path</em><big>)</big><a class="headerlink" href="#importlib.machinery.SourceFileLoader" title="Permalink to this definition">¶</a></dt> <dd><p>A concrete implementation of <a class="reference internal" href="#importlib.abc.SourceLoader" title="importlib.abc.SourceLoader"><tt class="xref py py-class docutils literal"><span class="pre">importlib.abc.SourceLoader</span></tt></a> by subclassing <a class="reference internal" href="#importlib.abc.FileLoader" title="importlib.abc.FileLoader"><tt class="xref py py-class docutils literal"><span class="pre">importlib.abc.FileLoader</span></tt></a> and providing some concrete implementations of other methods.</p> <p class="versionadded"> <span class="versionmodified">New in version 3.3.</span> </p> <dl class="attribute"> <dt id="importlib.machinery.SourceFileLoader.name"> <tt class="descname">name</tt><a class="headerlink" href="#importlib.machinery.SourceFileLoader.name" title="Permalink to this definition">¶</a></dt> <dd><p>The name of the module that this loader will handle.</p> </dd></dl> <dl class="attribute"> <dt id="importlib.machinery.SourceFileLoader.path"> <tt class="descname">path</tt><a class="headerlink" href="#importlib.machinery.SourceFileLoader.path" title="Permalink to this definition">¶</a></dt> <dd><p>The path to the source file.</p> </dd></dl> <dl class="method"> <dt id="importlib.machinery.SourceFileLoader.is_package"> <tt class="descname">is_package</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.machinery.SourceFileLoader.is_package" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if <a class="reference internal" href="#importlib.machinery.SourceFileLoader.path" title="importlib.machinery.SourceFileLoader.path"><tt class="xref py py-attr docutils literal"><span class="pre">path</span></tt></a> appears to be for a package.</p> </dd></dl> <dl class="method"> <dt id="importlib.machinery.SourceFileLoader.path_stats"> <tt class="descname">path_stats</tt><big>(</big><em>path</em><big>)</big><a class="headerlink" href="#importlib.machinery.SourceFileLoader.path_stats" title="Permalink to this definition">¶</a></dt> <dd><p>Concrete implementation of <a class="reference internal" href="#importlib.abc.SourceLoader.path_stats" title="importlib.abc.SourceLoader.path_stats"><tt class="xref py py-meth docutils literal"><span class="pre">importlib.abc.SourceLoader.path_stats()</span></tt></a>.</p> </dd></dl> <dl class="method"> <dt id="importlib.machinery.SourceFileLoader.set_data"> <tt class="descname">set_data</tt><big>(</big><em>path</em>, <em>data</em><big>)</big><a class="headerlink" href="#importlib.machinery.SourceFileLoader.set_data" title="Permalink to this definition">¶</a></dt> <dd><p>Concrete implementation of <a class="reference internal" href="#importlib.abc.SourceLoader.set_data" title="importlib.abc.SourceLoader.set_data"><tt class="xref py py-meth docutils literal"><span class="pre">importlib.abc.SourceLoader.set_data()</span></tt></a>.</p> </dd></dl> </dd></dl> <dl class="class"> <dt id="importlib.machinery.SourcelessFileLoader"> <em class="property">class </em><tt class="descclassname">importlib.machinery.</tt><tt class="descname">SourcelessFileLoader</tt><big>(</big><em>fullname</em>, <em>path</em><big>)</big><a class="headerlink" href="#importlib.machinery.SourcelessFileLoader" title="Permalink to this definition">¶</a></dt> <dd><p>A concrete implementation of <a class="reference internal" href="#importlib.abc.FileLoader" title="importlib.abc.FileLoader"><tt class="xref py py-class docutils literal"><span class="pre">importlib.abc.FileLoader</span></tt></a> which can import bytecode files (i.e. no source code files exist).</p> <p>Please note that direct use of bytecode files (and thus not source code files) inhibits your modules from being usable by all Python implementations or new versions of Python which change the bytecode format.</p> <p class="versionadded"> <span class="versionmodified">New in version 3.3.</span> </p> <dl class="attribute"> <dt id="importlib.machinery.SourcelessFileLoader.name"> <tt class="descname">name</tt><a class="headerlink" href="#importlib.machinery.SourcelessFileLoader.name" title="Permalink to this definition">¶</a></dt> <dd><p>The name of the module the loader will handle.</p> </dd></dl> <dl class="attribute"> <dt id="importlib.machinery.SourcelessFileLoader.path"> <tt class="descname">path</tt><a class="headerlink" href="#importlib.machinery.SourcelessFileLoader.path" title="Permalink to this definition">¶</a></dt> <dd><p>The path to the bytecode file.</p> </dd></dl> <dl class="method"> <dt id="importlib.machinery.SourcelessFileLoader.is_package"> <tt class="descname">is_package</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.machinery.SourcelessFileLoader.is_package" title="Permalink to this definition">¶</a></dt> <dd><p>Determines if the module is a package based on <a class="reference internal" href="#importlib.machinery.SourcelessFileLoader.path" title="importlib.machinery.SourcelessFileLoader.path"><tt class="xref py py-attr docutils literal"><span class="pre">path</span></tt></a>.</p> </dd></dl> <dl class="method"> <dt id="importlib.machinery.SourcelessFileLoader.get_code"> <tt class="descname">get_code</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.machinery.SourcelessFileLoader.get_code" title="Permalink to this definition">¶</a></dt> <dd><p>Returns the code object for <a class="reference internal" href="#importlib.machinery.SourcelessFileLoader.name" title="importlib.machinery.SourcelessFileLoader.name"><tt class="xref py py-attr docutils literal"><span class="pre">name</span></tt></a> created from <a class="reference internal" href="#importlib.machinery.SourcelessFileLoader.path" title="importlib.machinery.SourcelessFileLoader.path"><tt class="xref py py-attr docutils literal"><span class="pre">path</span></tt></a>.</p> </dd></dl> <dl class="method"> <dt id="importlib.machinery.SourcelessFileLoader.get_source"> <tt class="descname">get_source</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.machinery.SourcelessFileLoader.get_source" title="Permalink to this definition">¶</a></dt> <dd><p>Returns <tt class="xref docutils literal"><span class="pre">None</span></tt> as bytecode files have no source when this loader is used.</p> </dd></dl> </dd></dl> <dl class="class"> <dt id="importlib.machinery.ExtensionFileLoader"> <em class="property">class </em><tt class="descclassname">importlib.machinery.</tt><tt class="descname">ExtensionFileLoader</tt><big>(</big><em>fullname</em>, <em>path</em><big>)</big><a class="headerlink" href="#importlib.machinery.ExtensionFileLoader" title="Permalink to this definition">¶</a></dt> <dd><p>A concrete implementation of <a class="reference internal" href="#importlib.abc.InspectLoader" title="importlib.abc.InspectLoader"><tt class="xref py py-class docutils literal"><span class="pre">importlib.abc.InspectLoader</span></tt></a> for extension modules.</p> <p>The <em>fullname</em> argument specifies the name of the module the loader is to support. The <em>path</em> argument is the path to the extension module’s file.</p> <p class="versionadded"> <span class="versionmodified">New in version 3.3.</span> </p> <dl class="attribute"> <dt id="importlib.machinery.ExtensionFileLoader.name"> <tt class="descname">name</tt><a class="headerlink" href="#importlib.machinery.ExtensionFileLoader.name" title="Permalink to this definition">¶</a></dt> <dd><p>Name of the module the loader supports.</p> </dd></dl> <dl class="attribute"> <dt id="importlib.machinery.ExtensionFileLoader.path"> <tt class="descname">path</tt><a class="headerlink" href="#importlib.machinery.ExtensionFileLoader.path" title="Permalink to this definition">¶</a></dt> <dd><p>Path to the extension module.</p> </dd></dl> <dl class="method"> <dt id="importlib.machinery.ExtensionFileLoader.load_module"> <tt class="descname">load_module</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.machinery.ExtensionFileLoader.load_module" title="Permalink to this definition">¶</a></dt> <dd><p>Loads the extension module if and only if <em>fullname</em> is the same as <a class="reference internal" href="#importlib.machinery.ExtensionFileLoader.name" title="importlib.machinery.ExtensionFileLoader.name"><tt class="xref py py-attr docutils literal"><span class="pre">name</span></tt></a> or is <tt class="xref docutils literal"><span class="pre">None</span></tt>.</p> </dd></dl> <dl class="method"> <dt id="importlib.machinery.ExtensionFileLoader.is_package"> <tt class="descname">is_package</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.machinery.ExtensionFileLoader.is_package" title="Permalink to this definition">¶</a></dt> <dd><p>Returns <tt class="xref docutils literal"><span class="pre">True</span></tt> if the file path points to a package’s <tt class="docutils literal"><span class="pre">__init__</span></tt> module based on <a class="reference internal" href="#importlib.machinery.EXTENSION_SUFFIXES" title="importlib.machinery.EXTENSION_SUFFIXES"><tt class="xref py py-attr docutils literal"><span class="pre">EXTENSION_SUFFIXES</span></tt></a>.</p> </dd></dl> <dl class="method"> <dt id="importlib.machinery.ExtensionFileLoader.get_code"> <tt class="descname">get_code</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.machinery.ExtensionFileLoader.get_code" title="Permalink to this definition">¶</a></dt> <dd><p>Returns <tt class="xref docutils literal"><span class="pre">None</span></tt> as extension modules lack a code object.</p> </dd></dl> <dl class="method"> <dt id="importlib.machinery.ExtensionFileLoader.get_source"> <tt class="descname">get_source</tt><big>(</big><em>fullname</em><big>)</big><a class="headerlink" href="#importlib.machinery.ExtensionFileLoader.get_source" title="Permalink to this definition">¶</a></dt> <dd><p>Returns <tt class="xref docutils literal"><span class="pre">None</span></tt> as extension modules do not have source code.</p> </dd></dl> </dd></dl> </div> <div class="section" id="module-importlib.util"> <span id="importlib-util-utility-code-for-importers"></span><h2>30.6.5. <a class="reference internal" href="#module-importlib.util" title="importlib.util: Utility code for importers"><tt class="xref py py-mod docutils literal"><span class="pre">importlib.util</span></tt></a> – Utility code for importers<a class="headerlink" href="#module-importlib.util" title="Permalink to this headline">¶</a></h2> <p>This module contains the various objects that help in the construction of an <a class="reference internal" href="../glossary.html#term-importer"><em class="xref std std-term">importer</em></a>.</p> <dl class="function"> <dt id="importlib.util.resolve_name"> <tt class="descclassname">importlib.util.</tt><tt class="descname">resolve_name</tt><big>(</big><em>name</em>, <em>package</em><big>)</big><a class="headerlink" href="#importlib.util.resolve_name" title="Permalink to this definition">¶</a></dt> <dd><p>Resolve a relative module name to an absolute one.</p> <p>If <strong>name</strong> has no leading dots, then <strong>name</strong> is simply returned. This allows for usage such as <tt class="docutils literal"><span class="pre">importlib.util.resolve_name('sys',</span> <span class="pre">__package__)</span></tt> without doing a check to see if the <strong>package</strong> argument is needed.</p> <p><a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><tt class="xref py py-exc docutils literal"><span class="pre">ValueError</span></tt></a> is raised if <strong>name</strong> is a relative module name but package is a false value (e.g. <tt class="xref docutils literal"><span class="pre">None</span></tt> or the empty string). <a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><tt class="xref py py-exc docutils literal"><span class="pre">ValueError</span></tt></a> is also raised a relative name would escape its containing package (e.g. requesting <tt class="docutils literal"><span class="pre">..bacon</span></tt> from within the <tt class="docutils literal"><span class="pre">spam</span></tt> package).</p> <p class="versionadded"> <span class="versionmodified">New in version 3.3.</span> </p> </dd></dl> <dl class="function"> <dt id="importlib.util.module_for_loader"> <tt class="descclassname">@</tt><tt class="descclassname">importlib.util.</tt><tt class="descname">module_for_loader</tt><a class="headerlink" href="#importlib.util.module_for_loader" title="Permalink to this definition">¶</a></dt> <dd><p>A <a class="reference internal" href="../glossary.html#term-decorator"><em class="xref std std-term">decorator</em></a> for a <a class="reference internal" href="../glossary.html#term-loader"><em class="xref std std-term">loader</em></a> method, to handle selecting the proper module object to load with. The decorated method is expected to have a call signature taking two positional arguments (e.g. <tt class="docutils literal"><span class="pre">load_module(self,</span> <span class="pre">module)</span></tt>) for which the second argument will be the module <strong>object</strong> to be used by the loader. Note that the decorator will not work on static methods because of the assumption of two arguments.</p> <p>The decorated method will take in the <strong>name</strong> of the module to be loaded as expected for a <a class="reference internal" href="../glossary.html#term-loader"><em class="xref std std-term">loader</em></a>. If the module is not found in <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><tt class="xref py py-data docutils literal"><span class="pre">sys.modules</span></tt></a> then a new one is constructed with its <tt class="xref py py-attr docutils literal"><span class="pre">__name__</span></tt> attribute set to <strong>name</strong>, <tt class="xref py py-attr docutils literal"><span class="pre">__loader__</span></tt> set to <strong>self</strong>, and <tt class="xref py py-attr docutils literal"><span class="pre">__package__</span></tt> set if <a class="reference internal" href="#importlib.abc.InspectLoader.is_package" title="importlib.abc.InspectLoader.is_package"><tt class="xref py py-meth docutils literal"><span class="pre">importlib.abc.InspectLoader.is_package()</span></tt></a> is defined for <strong>self</strong> and does not raise <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><tt class="xref py py-exc docutils literal"><span class="pre">ImportError</span></tt></a> for <strong>name</strong>. If a new module is not needed then the module found in <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><tt class="xref py py-data docutils literal"><span class="pre">sys.modules</span></tt></a> will be passed into the method.</p> <p>If an exception is raised by the decorated method and a module was added to <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><tt class="xref py py-data docutils literal"><span class="pre">sys.modules</span></tt></a> it will be removed to prevent a partially initialized module from being in left in <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><tt class="xref py py-data docutils literal"><span class="pre">sys.modules</span></tt></a>. If the module was already in <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><tt class="xref py py-data docutils literal"><span class="pre">sys.modules</span></tt></a> then it is left alone.</p> <p>Use of this decorator handles all the details of which module object a loader should initialize as specified by <span class="target" id="index-15"></span><a class="pep reference external" href="http://www.python.org/dev/peps/pep-0302"><strong>PEP 302</strong></a> as best as possible.</p> <p class="versionchanged"> <span class="versionmodified">Changed in version 3.3:</span> <tt class="xref py py-attr docutils literal"><span class="pre">__loader__</span></tt> and <tt class="xref py py-attr docutils literal"><span class="pre">__package__</span></tt> are automatically set (when possible).</p> </dd></dl> <dl class="function"> <dt id="importlib.util.set_loader"> <tt class="descclassname">@</tt><tt class="descclassname">importlib.util.</tt><tt class="descname">set_loader</tt><a class="headerlink" href="#importlib.util.set_loader" title="Permalink to this definition">¶</a></dt> <dd><blockquote> <div>A <a class="reference internal" href="../glossary.html#term-decorator"><em class="xref std std-term">decorator</em></a> for a <a class="reference internal" href="../glossary.html#term-loader"><em class="xref std std-term">loader</em></a> method, to set the <tt class="xref py py-attr docutils literal"><span class="pre">__loader__</span></tt> attribute on loaded modules. If the attribute is already set the decorator does nothing. It is assumed that the first positional argument to the wrapped method (i.e. <tt class="docutils literal"><span class="pre">self</span></tt>) is what <tt class="xref py py-attr docutils literal"><span class="pre">__loader__</span></tt> should be set to.</div></blockquote> <div class="admonition note"> <p class="first admonition-title">Note</p> <p class="last">It is recommended that <a class="reference internal" href="#importlib.util.module_for_loader" title="importlib.util.module_for_loader"><tt class="xref py py-func docutils literal"><span class="pre">module_for_loader()</span></tt></a> be used over this decorator as it subsumes this functionality.</p> </div> </dd></dl> <dl class="function"> <dt id="importlib.util.set_package"> <tt class="descclassname">@</tt><tt class="descclassname">importlib.util.</tt><tt class="descname">set_package</tt><a class="headerlink" href="#importlib.util.set_package" title="Permalink to this definition">¶</a></dt> <dd><blockquote> <div><p>A <a class="reference internal" href="../glossary.html#term-decorator"><em class="xref std std-term">decorator</em></a> for a <a class="reference internal" href="../glossary.html#term-loader"><em class="xref std std-term">loader</em></a> to set the <tt class="xref py py-attr docutils literal"><span class="pre">__package__</span></tt> attribute on the module returned by the loader. If <tt class="xref py py-attr docutils literal"><span class="pre">__package__</span></tt> is set and has a value other than <tt class="xref docutils literal"><span class="pre">None</span></tt> it will not be changed. Note that the module returned by the loader is what has the attribute set on and not the module found in <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><tt class="xref py py-data docutils literal"><span class="pre">sys.modules</span></tt></a>.</p> <p>Reliance on this decorator is discouraged when it is possible to set <tt class="xref py py-attr docutils literal"><span class="pre">__package__</span></tt> before importing. By setting it beforehand the code for the module is executed with the attribute set and thus can be used by global level code during initialization.</p> </div></blockquote> <div class="admonition note"> <p class="first admonition-title">Note</p> <p class="last">It is recommended that <a class="reference internal" href="#importlib.util.module_for_loader" title="importlib.util.module_for_loader"><tt class="xref py py-func docutils literal"><span class="pre">module_for_loader()</span></tt></a> be used over this decorator as it subsumes this functionality.</p> </div> </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="#">30.6. <tt class="docutils literal"><span class="pre">importlib</span></tt> – An implementation of <tt class="docutils literal"><span class="pre">import</span></tt></a><ul> <li><a class="reference internal" href="#introduction">30.6.1. Introduction</a></li> <li><a class="reference internal" href="#functions">30.6.2. Functions</a></li> <li><a class="reference internal" href="#module-importlib.abc">30.6.3. <tt class="docutils literal"><span class="pre">importlib.abc</span></tt> – Abstract base classes related to import</a></li> <li><a class="reference internal" href="#module-importlib.machinery">30.6.4. <tt class="docutils literal"><span class="pre">importlib.machinery</span></tt> – Importers and path hooks</a></li> <li><a class="reference internal" href="#module-importlib.util">30.6.5. <tt class="docutils literal"><span class="pre">importlib.util</span></tt> – Utility code for importers</a></li> </ul> </li> </ul> <h4>Previous topic</h4> <p class="topless"><a href="runpy.html" title="previous chapter">30.5. <tt class="docutils literal"><span class="pre">runpy</span></tt> — Locating and executing Python modules</a></p> <h4>Next topic</h4> <p class="topless"><a href="language.html" title="next chapter">31. Python Language Services</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/importlib.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="../py-modindex.html" title="Python Module Index" >modules</a> |</li> <li class="right" > <a href="language.html" title="31. 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