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MS Windows Specific Services</a> »</li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body"> <div class="section" id="module-winreg"> <h1>32.3. <tt class="xref docutils literal"><span class="pre">winreg</span></tt> – Windows registry access<a class="headerlink" href="#module-winreg" title="Permalink to this headline">¶</a></h1> <p><em>Platforms: </em>Windows</p> <p>These functions expose the Windows registry API to Python. Instead of using an integer as the registry handle, a handle object is used to ensure that the handles are closed correctly, even if the programmer neglects to explicitly close them.</p> <p>This module exposes a very low-level interface to the Windows registry; it is expected that in the future a new <tt class="docutils literal"><span class="pre">winreg</span></tt> module will be created offering a higher-level interface to the registry API.</p> <p>This module offers the following functions:</p> <dl class="function"> <dt id="winreg.CloseKey"> <tt class="descclassname">winreg.</tt><tt class="descname">CloseKey</tt><big>(</big><em>hkey</em><big>)</big><a class="headerlink" href="#winreg.CloseKey" title="Permalink to this definition">¶</a></dt> <dd><p>Closes a previously opened registry key. The hkey argument specifies a previously opened key.</p> <p>Note that if <em>hkey</em> is not closed using this method (or via <tt class="xref docutils literal"><span class="pre">handle.Close()</span></tt>), it is closed when the <em>hkey</em> object is destroyed by Python.</p> </dd></dl> <dl class="function"> <dt id="winreg.ConnectRegistry"> <tt class="descclassname">winreg.</tt><tt class="descname">ConnectRegistry</tt><big>(</big><em>computer_name</em>, <em>key</em><big>)</big><a class="headerlink" href="#winreg.ConnectRegistry" title="Permalink to this definition">¶</a></dt> <dd><p>Establishes a connection to a predefined registry handle on another computer, and returns a <em>handle object</em></p> <p><em>computer_name</em> is the name of the remote computer, of the form <tt class="docutils literal"><span class="pre">r"\\computername"</span></tt>. If <tt class="xref docutils literal"><span class="pre">None</span></tt>, the local computer is used.</p> <p><em>key</em> is the predefined handle to connect to.</p> <p>The return value is the handle of the opened key. If the function fails, a <a title="exceptions.WindowsError" class="reference external" href="exceptions.html#exceptions.WindowsError"><tt class="xref docutils literal"><span class="pre">WindowsError</span></tt></a> exception is raised.</p> </dd></dl> <dl class="function"> <dt id="winreg.CreateKey"> <tt class="descclassname">winreg.</tt><tt class="descname">CreateKey</tt><big>(</big><em>key</em>, <em>sub_key</em><big>)</big><a class="headerlink" href="#winreg.CreateKey" title="Permalink to this definition">¶</a></dt> <dd><p>Creates or opens the specified key, returning a <em>handle object</em></p> <p><em>key</em> is an already open key, or one of the predefined <tt class="xref docutils literal"><span class="pre">HKEY_*</span></tt> constants.</p> <p><em>sub_key</em> is a string that names the key this method opens or creates.</p> <p>If <em>key</em> is one of the predefined keys, <em>sub_key</em> may be <tt class="xref docutils literal"><span class="pre">None</span></tt>. In that case, the handle returned is the same key handle passed in to the function.</p> <p>If the key already exists, this function opens the existing key.</p> <p>The return value is the handle of the opened key. If the function fails, a <a title="exceptions.WindowsError" class="reference external" href="exceptions.html#exceptions.WindowsError"><tt class="xref docutils literal"><span class="pre">WindowsError</span></tt></a> exception is raised.</p> </dd></dl> <dl class="function"> <dt id="winreg.DeleteKey"> <tt class="descclassname">winreg.</tt><tt class="descname">DeleteKey</tt><big>(</big><em>key</em>, <em>sub_key</em><big>)</big><a class="headerlink" href="#winreg.DeleteKey" title="Permalink to this definition">¶</a></dt> <dd><p>Deletes the specified key.</p> <p><em>key</em> is an already open key, or any one of the predefined <tt class="xref docutils literal"><span class="pre">HKEY_*</span></tt> constants.</p> <p><em>sub_key</em> is a string that must be a subkey of the key identified by the <em>key</em> parameter. This value must not be <tt class="xref docutils literal"><span class="pre">None</span></tt>, and the key may not have subkeys.</p> <p><em>This method can not delete keys with subkeys.</em></p> <p>If the method succeeds, the entire key, including all of its values, is removed. If the method fails, a <a title="exceptions.WindowsError" class="reference external" href="exceptions.html#exceptions.WindowsError"><tt class="xref docutils literal"><span class="pre">WindowsError</span></tt></a> exception is raised.</p> </dd></dl> <dl class="function"> <dt id="winreg.DeleteValue"> <tt class="descclassname">winreg.</tt><tt class="descname">DeleteValue</tt><big>(</big><em>key</em>, <em>value</em><big>)</big><a class="headerlink" href="#winreg.DeleteValue" title="Permalink to this definition">¶</a></dt> <dd><p>Removes a named value from a registry key.</p> <p><em>key</em> is an already open key, or one of the predefined <tt class="xref docutils literal"><span class="pre">HKEY_*</span></tt> constants.</p> <p><em>value</em> is a string that identifies the value to remove.</p> </dd></dl> <dl class="function"> <dt id="winreg.EnumKey"> <tt class="descclassname">winreg.</tt><tt class="descname">EnumKey</tt><big>(</big><em>key</em>, <em>index</em><big>)</big><a class="headerlink" href="#winreg.EnumKey" title="Permalink to this definition">¶</a></dt> <dd><p>Enumerates subkeys of an open registry key, returning a string.</p> <p><em>key</em> is an already open key, or any one of the predefined <tt class="xref docutils literal"><span class="pre">HKEY_*</span></tt> constants.</p> <p><em>index</em> is an integer that identifies the index of the key to retrieve.</p> <p>The function retrieves the name of one subkey each time it is called. It is typically called repeatedly until a <a title="exceptions.WindowsError" class="reference external" href="exceptions.html#exceptions.WindowsError"><tt class="xref docutils literal"><span class="pre">WindowsError</span></tt></a> exception is raised, indicating, no more values are available.</p> </dd></dl> <dl class="function"> <dt id="winreg.EnumValue"> <tt class="descclassname">winreg.</tt><tt class="descname">EnumValue</tt><big>(</big><em>key</em>, <em>index</em><big>)</big><a class="headerlink" href="#winreg.EnumValue" title="Permalink to this definition">¶</a></dt> <dd><p>Enumerates values of an open registry key, returning a tuple.</p> <p><em>key</em> is an already open key, or any one of the predefined <tt class="xref docutils literal"><span class="pre">HKEY_*</span></tt> constants.</p> <p><em>index</em> is an integer that identifies the index of the value to retrieve.</p> <p>The function retrieves the name of one subkey each time it is called. It is typically called repeatedly, until a <a title="exceptions.WindowsError" class="reference external" href="exceptions.html#exceptions.WindowsError"><tt class="xref docutils literal"><span class="pre">WindowsError</span></tt></a> exception is raised, indicating no more values.</p> <p>The result is a tuple of 3 items:</p> <table border="1" class="docutils"> <colgroup> <col width="14%" /> <col width="86%" /> </colgroup> <thead valign="bottom"> <tr><th class="head">Index</th> <th class="head">Meaning</th> </tr> </thead> <tbody valign="top"> <tr><td><tt class="docutils literal"><span class="pre">0</span></tt></td> <td>A string that identifies the value name</td> </tr> <tr><td><tt class="docutils literal"><span class="pre">1</span></tt></td> <td>An object that holds the value data, and whose type depends on the underlying registry type</td> </tr> <tr><td><tt class="docutils literal"><span class="pre">2</span></tt></td> <td>An integer that identifies the type of the value data</td> </tr> </tbody> </table> </dd></dl> <dl class="function"> <dt id="winreg.ExpandEnvironmentStrings"> <tt class="descclassname">winreg.</tt><tt class="descname">ExpandEnvironmentStrings</tt><big>(</big><em>unicode</em><big>)</big><a class="headerlink" href="#winreg.ExpandEnvironmentStrings" title="Permalink to this definition">¶</a></dt> <dd><p>Expands environment strings %NAME% in unicode string like const:<cite>REG_EXPAND_SZ</cite>:</p> <div class="highlight-python3"><div class="highlight"><pre><span class="gp">>>> </span><span class="n">ExpandEnvironmentStrings</span><span class="p">(</span><span class="s">u"%windir%"</span><span class="p">)</span> <span class="go">u"C:\\Windows"</span> </pre></div> </div> </dd></dl> <dl class="function"> <dt id="winreg.FlushKey"> <tt class="descclassname">winreg.</tt><tt class="descname">FlushKey</tt><big>(</big><em>key</em><big>)</big><a class="headerlink" href="#winreg.FlushKey" title="Permalink to this definition">¶</a></dt> <dd><p>Writes all the attributes of a key to the registry.</p> <p><em>key</em> is an already open key, or one of the predefined <tt class="xref docutils literal"><span class="pre">HKEY_*</span></tt> constants.</p> <p>It is not necessary to call <a title="winreg.FlushKey" class="reference internal" href="#winreg.FlushKey"><tt class="xref docutils literal"><span class="pre">FlushKey()</span></tt></a> to change a key. Registry changes are flushed to disk by the registry using its lazy flusher. Registry changes are also flushed to disk at system shutdown. Unlike <a title="winreg.CloseKey" class="reference internal" href="#winreg.CloseKey"><tt class="xref docutils literal"><span class="pre">CloseKey()</span></tt></a>, the <a title="winreg.FlushKey" class="reference internal" href="#winreg.FlushKey"><tt class="xref docutils literal"><span class="pre">FlushKey()</span></tt></a> method returns only when all the data has been written to the registry. An application should only call <a title="winreg.FlushKey" class="reference internal" href="#winreg.FlushKey"><tt class="xref docutils literal"><span class="pre">FlushKey()</span></tt></a> if it requires absolute certainty that registry changes are on disk.</p> <div class="admonition note"> <p class="first admonition-title">Note</p> <p class="last">If you don’t know whether a <a title="winreg.FlushKey" class="reference internal" href="#winreg.FlushKey"><tt class="xref docutils literal"><span class="pre">FlushKey()</span></tt></a> call is required, it probably isn’t.</p> </div> </dd></dl> <dl class="function"> <dt id="winreg.LoadKey"> <tt class="descclassname">winreg.</tt><tt class="descname">LoadKey</tt><big>(</big><em>key</em>, <em>sub_key</em>, <em>file_name</em><big>)</big><a class="headerlink" href="#winreg.LoadKey" title="Permalink to this definition">¶</a></dt> <dd><p>Creates a subkey under the specified key and stores registration information from a specified file into that subkey.</p> <p><em>key</em> is an already open key, or any of the predefined <tt class="xref docutils literal"><span class="pre">HKEY_*</span></tt> constants.</p> <p><em>sub_key</em> is a string that identifies the sub_key to load.</p> <p><em>file_name</em> is the name of the file to load registry data from. This file must have been created with the <a title="winreg.SaveKey" class="reference internal" href="#winreg.SaveKey"><tt class="xref docutils literal"><span class="pre">SaveKey()</span></tt></a> function. Under the file allocation table (FAT) file system, the filename may not have an extension.</p> <p>A call to LoadKey() fails if the calling process does not have the <tt class="xref docutils literal"><span class="pre">SE_RESTORE_PRIVILEGE</span></tt> privilege. Note that privileges are different than permissions - see the Win32 documentation for more details.</p> <p>If <em>key</em> is a handle returned by <a title="winreg.ConnectRegistry" class="reference internal" href="#winreg.ConnectRegistry"><tt class="xref docutils literal"><span class="pre">ConnectRegistry()</span></tt></a>, then the path specified in <em>fileName</em> is relative to the remote computer.</p> <p>The Win32 documentation implies <em>key</em> must be in the <tt class="xref docutils literal"><span class="pre">HKEY_USER</span></tt> or <tt class="xref docutils literal"><span class="pre">HKEY_LOCAL_MACHINE</span></tt> tree. This may or may not be true.</p> </dd></dl> <dl class="function"> <dt id="winreg.OpenKey"> <tt class="descclassname">winreg.</tt><tt class="descname">OpenKey</tt><big>(</big><em>key</em>, <em>sub_key</em><span class="optional">[</span>, <em>res=0</em><span class="optional">]</span><span class="optional">[</span>, <em>sam=KEY_READ</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#winreg.OpenKey" title="Permalink to this definition">¶</a></dt> <dd><p>Opens the specified key, returning a <em>handle object</em></p> <p><em>key</em> is an already open key, or any one of the predefined <tt class="xref docutils literal"><span class="pre">HKEY_*</span></tt> constants.</p> <p><em>sub_key</em> is a string that identifies the sub_key to open.</p> <p><em>res</em> is a reserved integer, and must be zero. The default is zero.</p> <p><em>sam</em> is an integer that specifies an access mask that describes the desired security access for the key. Default is <tt class="xref docutils literal"><span class="pre">KEY_READ</span></tt></p> <p>The result is a new handle to the specified key.</p> <p>If the function fails, <a title="exceptions.WindowsError" class="reference external" href="exceptions.html#exceptions.WindowsError"><tt class="xref docutils literal"><span class="pre">WindowsError</span></tt></a> is raised.</p> </dd></dl> <dl class="function"> <dt id="winreg.OpenKeyEx"> <tt class="descclassname">winreg.</tt><tt class="descname">OpenKeyEx</tt><big>(</big><big>)</big><a class="headerlink" href="#winreg.OpenKeyEx" title="Permalink to this definition">¶</a></dt> <dd>The functionality of <a title="winreg.OpenKeyEx" class="reference internal" href="#winreg.OpenKeyEx"><tt class="xref docutils literal"><span class="pre">OpenKeyEx()</span></tt></a> is provided via <a title="winreg.OpenKey" class="reference internal" href="#winreg.OpenKey"><tt class="xref docutils literal"><span class="pre">OpenKey()</span></tt></a>, by the use of default arguments.</dd></dl> <dl class="function"> <dt id="winreg.QueryInfoKey"> <tt class="descclassname">winreg.</tt><tt class="descname">QueryInfoKey</tt><big>(</big><em>key</em><big>)</big><a class="headerlink" href="#winreg.QueryInfoKey" title="Permalink to this definition">¶</a></dt> <dd><p>Returns information about a key, as a tuple.</p> <p><em>key</em> is an already open key, or one of the predefined <tt class="xref docutils literal"><span class="pre">HKEY_*</span></tt> constants.</p> <p>The result is a tuple of 3 items:</p> <table border="1" class="docutils"> <colgroup> <col width="13%" /> <col width="87%" /> </colgroup> <thead valign="bottom"> <tr><th class="head">Index</th> <th class="head">Meaning</th> </tr> </thead> <tbody valign="top"> <tr><td><tt class="docutils literal"><span class="pre">0</span></tt></td> <td>An integer giving the number of sub keys this key has.</td> </tr> <tr><td><tt class="docutils literal"><span class="pre">1</span></tt></td> <td>An integer giving the number of values this key has.</td> </tr> <tr><td><tt class="docutils literal"><span class="pre">2</span></tt></td> <td>An integer giving when the key was last modified (if available) as 100’s of nanoseconds since Jan 1, 1600.</td> </tr> </tbody> </table> </dd></dl> <dl class="function"> <dt id="winreg.QueryValue"> <tt class="descclassname">winreg.</tt><tt class="descname">QueryValue</tt><big>(</big><em>key</em>, <em>sub_key</em><big>)</big><a class="headerlink" href="#winreg.QueryValue" title="Permalink to this definition">¶</a></dt> <dd><p>Retrieves the unnamed value for a key, as a string</p> <p><em>key</em> is an already open key, or one of the predefined <tt class="xref docutils literal"><span class="pre">HKEY_*</span></tt> constants.</p> <p><em>sub_key</em> is a string that holds the name of the subkey with which the value is associated. If this parameter is <tt class="xref docutils literal"><span class="pre">None</span></tt> or empty, the function retrieves the value set by the <a title="winreg.SetValue" class="reference internal" href="#winreg.SetValue"><tt class="xref docutils literal"><span class="pre">SetValue()</span></tt></a> method for the key identified by <em>key</em>.</p> <p>Values in the registry have name, type, and data components. This method retrieves the data for a key’s first value that has a NULL name. But the underlying API call doesn’t return the type, so always use <a title="winreg.QueryValueEx" class="reference internal" href="#winreg.QueryValueEx"><tt class="xref docutils literal"><span class="pre">QueryValueEx()</span></tt></a> if possible.</p> </dd></dl> <dl class="function"> <dt id="winreg.QueryValueEx"> <tt class="descclassname">winreg.</tt><tt class="descname">QueryValueEx</tt><big>(</big><em>key</em>, <em>value_name</em><big>)</big><a class="headerlink" href="#winreg.QueryValueEx" title="Permalink to this definition">¶</a></dt> <dd><p>Retrieves the type and data for a specified value name associated with an open registry key.</p> <p><em>key</em> is an already open key, or one of the predefined <tt class="xref docutils literal"><span class="pre">HKEY_*</span></tt> constants.</p> <p><em>value_name</em> is a string indicating the value to query.</p> <p>The result is a tuple of 2 items:</p> <table border="1" class="docutils"> <colgroup> <col width="15%" /> <col width="85%" /> </colgroup> <thead valign="bottom"> <tr><th class="head">Index</th> <th class="head">Meaning</th> </tr> </thead> <tbody valign="top"> <tr><td><tt class="docutils literal"><span class="pre">0</span></tt></td> <td>The value of the registry item.</td> </tr> <tr><td><tt class="docutils literal"><span class="pre">1</span></tt></td> <td>An integer giving the registry type for this value.</td> </tr> </tbody> </table> </dd></dl> <dl class="function"> <dt id="winreg.SaveKey"> <tt class="descclassname">winreg.</tt><tt class="descname">SaveKey</tt><big>(</big><em>key</em>, <em>file_name</em><big>)</big><a class="headerlink" href="#winreg.SaveKey" title="Permalink to this definition">¶</a></dt> <dd><p>Saves the specified key, and all its subkeys to the specified file.</p> <p><em>key</em> is an already open key, or one of the predefined <tt class="xref docutils literal"><span class="pre">HKEY_*</span></tt> constants.</p> <p><em>file_name</em> is the name of the file to save registry data to. This file cannot already exist. If this filename includes an extension, it cannot be used on file allocation table (FAT) file systems by the <a title="winreg.LoadKey" class="reference internal" href="#winreg.LoadKey"><tt class="xref docutils literal"><span class="pre">LoadKey()</span></tt></a>, <tt class="xref docutils literal"><span class="pre">ReplaceKey()</span></tt> or <tt class="xref docutils literal"><span class="pre">RestoreKey()</span></tt> methods.</p> <p>If <em>key</em> represents a key on a remote computer, the path described by <em>file_name</em> is relative to the remote computer. The caller of this method must possess the <tt class="xref docutils literal"><span class="pre">SeBackupPrivilege</span></tt> security privilege. Note that privileges are different than permissions - see the Win32 documentation for more details.</p> <p>This function passes NULL for <em>security_attributes</em> to the API.</p> </dd></dl> <dl class="function"> <dt id="winreg.SetValue"> <tt class="descclassname">winreg.</tt><tt class="descname">SetValue</tt><big>(</big><em>key</em>, <em>sub_key</em>, <em>type</em>, <em>value</em><big>)</big><a class="headerlink" href="#winreg.SetValue" title="Permalink to this definition">¶</a></dt> <dd><p>Associates a value with a specified key.</p> <p><em>key</em> is an already open key, or one of the predefined <tt class="xref docutils literal"><span class="pre">HKEY_*</span></tt> constants.</p> <p><em>sub_key</em> is a string that names the subkey with which the value is associated.</p> <p><em>type</em> is an integer that specifies the type of the data. Currently this must be <tt class="xref docutils literal"><span class="pre">REG_SZ</span></tt>, meaning only strings are supported. Use the <a title="winreg.SetValueEx" class="reference internal" href="#winreg.SetValueEx"><tt class="xref docutils literal"><span class="pre">SetValueEx()</span></tt></a> function for support for other data types.</p> <p><em>value</em> is a string that specifies the new value.</p> <p>If the key specified by the <em>sub_key</em> parameter does not exist, the SetValue function creates it.</p> <p>Value lengths are limited by available memory. Long values (more than 2048 bytes) should be stored as files with the filenames stored in the configuration registry. This helps the registry perform efficiently.</p> <p>The key identified by the <em>key</em> parameter must have been opened with <tt class="xref docutils literal"><span class="pre">KEY_SET_VALUE</span></tt> access.</p> </dd></dl> <dl class="function"> <dt id="winreg.SetValueEx"> <tt class="descclassname">winreg.</tt><tt class="descname">SetValueEx</tt><big>(</big><em>key</em>, <em>value_name</em>, <em>reserved</em>, <em>type</em>, <em>value</em><big>)</big><a class="headerlink" href="#winreg.SetValueEx" title="Permalink to this definition">¶</a></dt> <dd><p>Stores data in the value field of an open registry key.</p> <p><em>key</em> is an already open key, or one of the predefined <tt class="xref docutils literal"><span class="pre">HKEY_*</span></tt> constants.</p> <p><em>value_name</em> is a string that names the subkey with which the value is associated.</p> <p><em>type</em> is an integer that specifies the type of the data. This should be one of the following constants defined in this module:</p> <table border="1" class="docutils"> <colgroup> <col width="43%" /> <col width="57%" /> </colgroup> <thead valign="bottom"> <tr><th class="head">Constant</th> <th class="head">Meaning</th> </tr> </thead> <tbody valign="top"> <tr><td><tt class="xref docutils literal"><span class="pre">REG_BINARY</span></tt></td> <td>Binary data in any form.</td> </tr> <tr><td><tt class="xref docutils literal"><span class="pre">REG_DWORD</span></tt></td> <td>A 32-bit number.</td> </tr> <tr><td><tt class="xref docutils literal"><span class="pre">REG_DWORD_LITTLE_ENDIAN</span></tt></td> <td>A 32-bit number in little-endian format.</td> </tr> <tr><td><tt class="xref docutils literal"><span class="pre">REG_DWORD_BIG_ENDIAN</span></tt></td> <td>A 32-bit number in big-endian format.</td> </tr> <tr><td><tt class="xref docutils literal"><span class="pre">REG_EXPAND_SZ</span></tt></td> <td>Null-terminated string containing references to environment variables (<tt class="docutils literal"><span class="pre">%PATH%</span></tt>).</td> </tr> <tr><td><tt class="xref docutils literal"><span class="pre">REG_LINK</span></tt></td> <td>A Unicode symbolic link.</td> </tr> <tr><td><tt class="xref docutils literal"><span class="pre">REG_MULTI_SZ</span></tt></td> <td>A sequence of null-terminated strings, terminated by two null characters. (Python handles this termination automatically.)</td> </tr> <tr><td><tt class="xref docutils literal"><span class="pre">REG_NONE</span></tt></td> <td>No defined value type.</td> </tr> <tr><td><tt class="xref docutils literal"><span class="pre">REG_RESOURCE_LIST</span></tt></td> <td>A device-driver resource list.</td> </tr> <tr><td><tt class="xref docutils literal"><span class="pre">REG_SZ</span></tt></td> <td>A null-terminated string.</td> </tr> </tbody> </table> <p><em>reserved</em> can be anything - zero is always passed to the API.</p> <p><em>value</em> is a string that specifies the new value.</p> <p>This method can also set additional value and type information for the specified key. The key identified by the key parameter must have been opened with <tt class="xref docutils literal"><span class="pre">KEY_SET_VALUE</span></tt> access.</p> <p>To open the key, use the <tt class="xref docutils literal"><span class="pre">CreateKeyEx()</span></tt> or <a title="winreg.OpenKey" class="reference internal" href="#winreg.OpenKey"><tt class="xref docutils literal"><span class="pre">OpenKey()</span></tt></a> methods.</p> <p>Value lengths are limited by available memory. Long values (more than 2048 bytes) should be stored as files with the filenames stored in the configuration registry. This helps the registry perform efficiently.</p> </dd></dl> <div class="section" id="registry-handle-objects"> <span id="handle-object"></span><h2>32.3.1. Registry Handle Objects<a class="headerlink" href="#registry-handle-objects" title="Permalink to this headline">¶</a></h2> <p>This object wraps a Windows HKEY object, automatically closing it when the object is destroyed. To guarantee cleanup, you can call either the <tt class="xref docutils literal"><span class="pre">Close()</span></tt> method on the object, or the <a title="winreg.CloseKey" class="reference internal" href="#winreg.CloseKey"><tt class="xref docutils literal"><span class="pre">CloseKey()</span></tt></a> function.</p> <p>All registry functions in this module return one of these objects.</p> <p>All registry functions in this module which accept a handle object also accept an integer, however, use of the handle object is encouraged.</p> <p>Handle objects provide semantics for <a title="object.__bool__" class="reference external" href="../reference/datamodel.html#object.__bool__"><tt class="xref docutils literal"><span class="pre">__bool__()</span></tt></a> - thus</p> <div class="highlight-python3"><div class="highlight"><pre><span class="k">if</span> <span class="n">handle</span><span class="p">:</span> <span class="nb">print</span><span class="p">(</span><span class="s">"Yes"</span><span class="p">)</span> </pre></div> </div> <p>will print <tt class="docutils literal"><span class="pre">Yes</span></tt> if the handle is currently valid (has not been closed or detached).</p> <p>The object also support comparison semantics, so handle objects will compare true if they both reference the same underlying Windows handle value.</p> <p>Handle objects can be converted to an integer (e.g., using the built-in <a title="int" class="reference external" href="functions.html#int"><tt class="xref docutils literal"><span class="pre">int()</span></tt></a> function), in which case the underlying Windows handle value is returned. You can also use the <tt class="xref docutils literal"><span class="pre">Detach()</span></tt> method to return the integer handle, and also disconnect the Windows handle from the handle object.</p> <dl class="method"> <dt id="winreg.PyHKEY.Close"> <tt class="descclassname">PyHKEY.</tt><tt class="descname">Close</tt><big>(</big><big>)</big><a class="headerlink" href="#winreg.PyHKEY.Close" title="Permalink to this definition">¶</a></dt> <dd><p>Closes the underlying Windows handle.</p> <p>If the handle is already closed, no error is raised.</p> </dd></dl> <dl class="method"> <dt id="winreg.PyHKEY.Detach"> <tt class="descclassname">PyHKEY.</tt><tt class="descname">Detach</tt><big>(</big><big>)</big><a class="headerlink" href="#winreg.PyHKEY.Detach" title="Permalink to this definition">¶</a></dt> <dd><p>Detaches the Windows handle from the handle object.</p> <p>The result is an integer that holds the value of the handle before it is detached. If the handle is already detached or closed, this will return zero.</p> <p>After calling this function, the handle is effectively invalidated, but the handle is not closed. You would call this function when you need the underlying Win32 handle to exist beyond the lifetime of the handle object.</p> </dd></dl> <dl class="method"> <dt id="winreg.PyHKEY.__enter__"> <tt class="descclassname">PyHKEY.</tt><tt class="descname">__enter__</tt><big>(</big><big>)</big><a class="headerlink" href="#winreg.PyHKEY.__enter__" title="Permalink to this definition">¶</a></dt> <dt id="winreg.PyHKEY.__exit__"> <tt class="descclassname">PyHKEY.</tt><tt class="descname">__exit__</tt><big>(</big><em>*exc_info</em><big>)</big><a class="headerlink" href="#winreg.PyHKEY.__exit__" title="Permalink to this definition">¶</a></dt> <dd><p>The HKEY object implements <a title="winreg.PyHKEY.__enter__" class="reference internal" href="#winreg.PyHKEY.__enter__"><tt class="xref docutils literal"><span class="pre">__enter__()</span></tt></a> and <a title="winreg.PyHKEY.__exit__" class="reference internal" href="#winreg.PyHKEY.__exit__"><tt class="xref docutils literal"><span class="pre">__exit__()</span></tt></a> and thus supports the context protocol for the <a class="reference external" href="../reference/compound_stmts.html#with"><tt class="xref docutils literal"><span class="pre">with</span></tt></a> statement:</p> <div class="highlight-python3"><div class="highlight"><pre><span class="k">with</span> <span class="n">OpenKey</span><span class="p">(</span><span class="n">HKEY_LOCAL_MACHINE</span><span class="p">,</span> <span class="s">"foo"</span><span class="p">)</span> <span class="k">as</span> <span class="n">key</span><span class="p">:</span> <span class="c"># ... work with key ...</span> </pre></div> </div> <p>will automatically close <em>key</em> when control leaves the <a class="reference external" href="../reference/compound_stmts.html#with"><tt class="xref docutils literal"><span class="pre">with</span></tt></a> block.</p> </dd></dl> </div> </div> </div> </div> </div> <div class="sphinxsidebar"> <div class="sphinxsidebarwrapper"> <h3><a href="../contents.html">Table Of Contents</a></h3> <ul> <li><a class="reference external" href="">32.3. <tt class="docutils literal"><span class="pre">winreg</span></tt> – Windows registry access</a><ul> <li><a class="reference external" href="#registry-handle-objects">32.3.1. Registry Handle Objects</a></li> </ul> </li> </ul> <h4>Previous topic</h4> <p class="topless"><a href="msvcrt.html" title="previous chapter">32.2. <tt class="docutils literal docutils literal docutils literal"><span class="pre">msvcrt</span></tt> – Useful routines from the MS VC++ runtime</a></p> <h4>Next topic</h4> <p class="topless"><a href="winsound.html" title="next chapter">32.4. <tt class="docutils literal docutils literal"><span class="pre">winsound</span></tt> — Sound-playing interface for Windows</a></p> <h3>This Page</h3> <ul class="this-page-menu"> <li><a href="../_sources/library/winreg.txt" rel="nofollow">Show Source</a></li> </ul> <div id="searchbox" style="display: none"> <h3>Quick search</h3> <form class="search" action="../search.html" method="get"> <input type="text" name="q" size="18" /> <input type="submit" value="Go" /> <input type="hidden" name="check_keywords" value="yes" /> <input type="hidden" name="area" value="default" /> </form> <p class="searchtip" style="font-size: 90%"> Enter search terms or a module, class or function name. </p> </div> <script type="text/javascript">$('#searchbox').show(0);</script> </div> </div> <div class="clearer"></div> </div> <div class="related"> <h3>Navigation</h3> <ul> <li class="right" style="margin-right: 10px"> <a href="../genindex.html" title="General Index" >index</a></li> <li class="right" > <a href="../modindex.html" title="Global Module Index" >modules</a> |</li> <li class="right" > <a href="winsound.html" title="32.4. winsound — Sound-playing interface for Windows" >next</a> |</li> <li class="right" > <a href="msvcrt.html" title="32.2. msvcrt – Useful routines from the MS VC++ runtime" >previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="../index.html">Python v3.1.1 documentation</a> »</li> <li><a href="index.html" >The Python Standard Library</a> »</li> <li><a href="windows.html" >32. 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