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Python Language Services</a> »</li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body"> <div class="section" id="module-pickletools"> <span id="pickletools-tools-for-pickle-developers"></span><h1>31.13. <a class="reference internal" href="#module-pickletools" title="pickletools: Contains extensive comments about the pickle protocols and pickle-machine opcodes, as well as some useful functions."><tt class="xref py py-mod docutils literal"><span class="pre">pickletools</span></tt></a> — Tools for pickle developers<a class="headerlink" href="#module-pickletools" title="Permalink to this headline">¶</a></h1> <p class="versionadded"> <span class="versionmodified">New in version 2.3.</span></p> <p><strong>Source code:</strong> <a class="reference external" href="http://hg.python.org/cpython/file/2.7/Lib/pickletools.py">Lib/pickletools.py</a></p> <hr class="docutils" /> <p>This module contains various constants relating to the intimate details of the <a class="reference internal" href="pickle.html#module-pickle" title="pickle: Convert Python objects to streams of bytes and back."><tt class="xref py py-mod docutils literal"><span class="pre">pickle</span></tt></a> module, some lengthy comments about the implementation, and a few useful functions for analyzing pickled data. The contents of this module are useful for Python core developers who are working on the <a class="reference internal" href="pickle.html#module-pickle" title="pickle: Convert Python objects to streams of bytes and back."><tt class="xref py py-mod docutils literal"><span class="pre">pickle</span></tt></a> and <a class="reference internal" href="pickle.html#module-cPickle" title="cPickle: Faster version of pickle, but not subclassable."><tt class="xref py py-mod docutils literal"><span class="pre">cPickle</span></tt></a> implementations; ordinary users of the <a class="reference internal" href="pickle.html#module-pickle" title="pickle: Convert Python objects to streams of bytes and back."><tt class="xref py py-mod docutils literal"><span class="pre">pickle</span></tt></a> module probably won’t find the <a class="reference internal" href="#module-pickletools" title="pickletools: Contains extensive comments about the pickle protocols and pickle-machine opcodes, as well as some useful functions."><tt class="xref py py-mod docutils literal"><span class="pre">pickletools</span></tt></a> module relevant.</p> <dl class="function"> <dt id="pickletools.dis"> <tt class="descclassname">pickletools.</tt><tt class="descname">dis</tt><big>(</big><em>pickle</em>, <em>out=None</em>, <em>memo=None</em>, <em>indentlevel=4</em><big>)</big><a class="headerlink" href="#pickletools.dis" title="Permalink to this definition">¶</a></dt> <dd><p>Outputs a symbolic disassembly of the pickle to the file-like object <em>out</em>, defaulting to <tt class="docutils literal"><span class="pre">sys.stdout</span></tt>. <em>pickle</em> can be a string or a file-like object. <em>memo</em> can be a Python dictionary that will be used as the pickle’s memo; it can be used to perform disassemblies across multiple pickles created by the same pickler. Successive levels, indicated by <tt class="docutils literal"><span class="pre">MARK</span></tt> opcodes in the stream, are indented by <em>indentlevel</em> spaces.</p> </dd></dl> <dl class="function"> <dt id="pickletools.genops"> <tt class="descclassname">pickletools.</tt><tt class="descname">genops</tt><big>(</big><em>pickle</em><big>)</big><a class="headerlink" href="#pickletools.genops" title="Permalink to this definition">¶</a></dt> <dd><p>Provides an <a class="reference internal" href="../glossary.html#term-iterator"><em class="xref std std-term">iterator</em></a> over all of the opcodes in a pickle, returning a sequence of <tt class="docutils literal"><span class="pre">(opcode,</span> <span class="pre">arg,</span> <span class="pre">pos)</span></tt> triples. <em>opcode</em> is an instance of an <tt class="xref py py-class docutils literal"><span class="pre">OpcodeInfo</span></tt> class; <em>arg</em> is the decoded value, as a Python object, of the opcode’s argument; <em>pos</em> is the position at which this opcode is located. <em>pickle</em> can be a string or a file-like object.</p> </dd></dl> <dl class="function"> <dt id="pickletools.optimize"> <tt class="descclassname">pickletools.</tt><tt class="descname">optimize</tt><big>(</big><em>picklestring</em><big>)</big><a class="headerlink" href="#pickletools.optimize" title="Permalink to this definition">¶</a></dt> <dd><p>Returns a new equivalent pickle string after eliminating unused <tt class="docutils literal"><span class="pre">PUT</span></tt> opcodes. The optimized pickle is shorter, takes less transmission time, requires less storage space, and unpickles more efficiently.</p> <p class="versionadded"> <span class="versionmodified">New in version 2.6.</span></p> </dd></dl> </div> </div> </div> </div> <div class="sphinxsidebar"> <div class="sphinxsidebarwrapper"> <h4>Previous topic</h4> <p class="topless"><a href="dis.html" title="previous chapter">31.12. <tt class="docutils literal"><span class="pre">dis</span></tt> — Disassembler for Python bytecode</a></p> <h4>Next topic</h4> <p class="topless"><a href="compiler.html" title="next chapter">32. 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