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<li><a class="reference internal" href="#"><code class="xref py py-mod docutils literal notranslate"><span class="pre">copyreg</span></code> — Register <code class="xref py py-mod docutils literal notranslate"><span class="pre">pickle</span></code> support functions</a><ul>
<li><a class="reference internal" href="#example">Example</a></li>
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<section id="module-copyreg">
<span id="copyreg-register-pickle-support-functions"></span><h1><code class="xref py py-mod docutils literal notranslate"><span class="pre">copyreg</span></code> — Register <code class="xref py py-mod docutils literal notranslate"><span class="pre">pickle</span></code> support functions<a class="headerlink" href="#module-copyreg" title="Link to this heading">¶</a></h1>
<p><strong>Source code:</strong> <a class="extlink-source reference external" href="https://github.com/python/cpython/tree/3.13/Lib/copyreg.py">Lib/copyreg.py</a></p>
<hr class="docutils" id="index-0" />
<p>The <a class="reference internal" href="#module-copyreg" title="copyreg: Register pickle support functions."><code class="xref py py-mod docutils literal notranslate"><span class="pre">copyreg</span></code></a> module offers a way to define functions used while pickling
specific objects. The <a class="reference internal" href="pickle.html#module-pickle" title="pickle: Convert Python objects to streams of bytes and back."><code class="xref py py-mod docutils literal notranslate"><span class="pre">pickle</span></code></a> and <a class="reference internal" href="copy.html#module-copy" title="copy: Shallow and deep copy operations."><code class="xref py py-mod docutils literal notranslate"><span class="pre">copy</span></code></a> modules use those functions
when pickling/copying those objects. The module provides configuration
information about object constructors which are not classes.
Such constructors may be factory functions or class instances.</p>
<dl class="py function">
<dt class="sig sig-object py" id="copyreg.constructor">
<span class="sig-prename descclassname"><span class="pre">copyreg.</span></span><span class="sig-name descname"><span class="pre">constructor</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">object</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#copyreg.constructor" title="Link to this definition">¶</a></dt>
<dd><p>Declares <em>object</em> to be a valid constructor. If <em>object</em> is not callable (and
hence not valid as a constructor), raises <a class="reference internal" href="exceptions.html#TypeError" title="TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a>.</p>
</dd></dl>
<dl class="py function">
<dt class="sig sig-object py" id="copyreg.pickle">
<span class="sig-prename descclassname"><span class="pre">copyreg.</span></span><span class="sig-name descname"><span class="pre">pickle</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">type</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">function</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">constructor_ob</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#copyreg.pickle" title="Link to this definition">¶</a></dt>
<dd><p>Declares that <em>function</em> should be used as a “reduction” function for objects
of type <em>type</em>. <em>function</em> must return either a string or a tuple
containing between two and six elements. See the <a class="reference internal" href="pickle.html#pickle.Pickler.dispatch_table" title="pickle.Pickler.dispatch_table"><code class="xref py py-attr docutils literal notranslate"><span class="pre">dispatch_table</span></code></a>
for more details on the interface of <em>function</em>.</p>
<p>The <em>constructor_ob</em> parameter is a legacy feature and is now ignored, but if
passed it must be a callable.</p>
<p>Note that the <a class="reference internal" href="pickle.html#pickle.Pickler.dispatch_table" title="pickle.Pickler.dispatch_table"><code class="xref py py-attr docutils literal notranslate"><span class="pre">dispatch_table</span></code></a> attribute of a pickler
object or subclass of <a class="reference internal" href="pickle.html#pickle.Pickler" title="pickle.Pickler"><code class="xref py py-class docutils literal notranslate"><span class="pre">pickle.Pickler</span></code></a> can also be used for
declaring reduction functions.</p>
</dd></dl>
<section id="example">
<h2>Example<a class="headerlink" href="#example" title="Link to this heading">¶</a></h2>
<p>The example below would like to show how to register a pickle function and how
it will be used:</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span><span class="w"> </span><span class="nn">copyreg</span><span class="o">,</span><span class="w"> </span><span class="nn">copy</span><span class="o">,</span><span class="w"> </span><span class="nn">pickle</span>
<span class="gp">>>> </span><span class="k">class</span><span class="w"> </span><span class="nc">C</span><span class="p">:</span>
<span class="gp">... </span> <span class="k">def</span><span class="w"> </span><span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">a</span><span class="p">):</span>
<span class="gp">... </span> <span class="bp">self</span><span class="o">.</span><span class="n">a</span> <span class="o">=</span> <span class="n">a</span>
<span class="gp">...</span>
<span class="gp">>>> </span><span class="k">def</span><span class="w"> </span><span class="nf">pickle_c</span><span class="p">(</span><span class="n">c</span><span class="p">):</span>
<span class="gp">... </span> <span class="nb">print</span><span class="p">(</span><span class="s2">"pickling a C instance..."</span><span class="p">)</span>
<span class="gp">... </span> <span class="k">return</span> <span class="n">C</span><span class="p">,</span> <span class="p">(</span><span class="n">c</span><span class="o">.</span><span class="n">a</span><span class="p">,)</span>
<span class="gp">...</span>
<span class="gp">>>> </span><span class="n">copyreg</span><span class="o">.</span><span class="n">pickle</span><span class="p">(</span><span class="n">C</span><span class="p">,</span> <span class="n">pickle_c</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">c</span> <span class="o">=</span> <span class="n">C</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">d</span> <span class="o">=</span> <span class="n">copy</span><span class="o">.</span><span class="n">copy</span><span class="p">(</span><span class="n">c</span><span class="p">)</span>
<span class="go">pickling a C instance...</span>
<span class="gp">>>> </span><span class="n">p</span> <span class="o">=</span> <span class="n">pickle</span><span class="o">.</span><span class="n">dumps</span><span class="p">(</span><span class="n">c</span><span class="p">)</span>
<span class="go">pickling a C instance...</span>
</pre></div>
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<li><a class="reference internal" href="#"><code class="xref py py-mod docutils literal notranslate"><span class="pre">copyreg</span></code> — Register <code class="xref py py-mod docutils literal notranslate"><span class="pre">pickle</span></code> support functions</a><ul>
<li><a class="reference internal" href="#example">Example</a></li>
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