<!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta charset="utf-8" /> <title>Complex Number Objects — Python 3.7.4 documentation</title> <link rel="stylesheet" href="../_static/pydoctheme.css" type="text/css" /> <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> <script type="text/javascript" id="documentation_options" data-url_root="../" src="../_static/documentation_options.js"></script> <script type="text/javascript" src="../_static/jquery.js"></script> <script type="text/javascript" src="../_static/underscore.js"></script> <script type="text/javascript" src="../_static/doctools.js"></script> <script type="text/javascript" src="../_static/language_data.js"></script> <script type="text/javascript" src="../_static/sidebar.js"></script> <link rel="search" type="application/opensearchdescription+xml" title="Search within Python 3.7.4 documentation" href="../_static/opensearch.xml"/> <link rel="author" title="About these documents" href="../about.html" /> <link rel="index" title="Index" href="../genindex.html" /> <link rel="search" title="Search" href="../search.html" /> <link rel="copyright" title="Copyright" href="../copyright.html" /> <link rel="next" title="Bytes Objects" href="bytes.html" /> <link rel="prev" title="Floating Point Objects" href="float.html" /> <link rel="shortcut icon" type="image/png" href="../_static/py.png" /> <link rel="canonical" href="https://docs.python.org/3/c-api/complex.html" /> <script type="text/javascript" src="../_static/copybutton.js"></script> <script type="text/javascript" src="../_static/switchers.js"></script> <style> @media only screen { table.full-width-table { width: 100%; } } </style> </head><body> <div class="related" role="navigation" aria-label="related navigation"> <h3>Navigation</h3> <ul> <li class="right" style="margin-right: 10px"> <a href="../genindex.html" title="General Index" accesskey="I">index</a></li> <li class="right" > <a href="../py-modindex.html" title="Python Module Index" >modules</a> |</li> <li class="right" > <a href="bytes.html" title="Bytes Objects" accesskey="N">next</a> |</li> <li class="right" > <a href="float.html" title="Floating Point Objects" accesskey="P">previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="https://www.python.org/">Python</a> »</li> <li> <span class="language_switcher_placeholder">en</span> <span class="version_switcher_placeholder">3.7.4</span> <a href="../index.html">Documentation </a> » </li> <li class="nav-item nav-item-1"><a href="index.html" >Python/C API Reference Manual</a> »</li> <li class="nav-item nav-item-2"><a href="concrete.html" accesskey="U">Concrete Objects Layer</a> »</li> <li class="right"> <div class="inline-search" style="display: none" role="search"> <form class="inline-search" action="../search.html" method="get"> <input placeholder="Quick search" type="text" name="q" /> <input type="submit" value="Go" /> <input type="hidden" name="check_keywords" value="yes" /> <input type="hidden" name="area" value="default" /> </form> </div> <script type="text/javascript">$('.inline-search').show(0);</script> | </li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body" role="main"> <div class="section" id="complex-number-objects"> <span id="complexobjects"></span><h1>Complex Number Objects<a class="headerlink" href="#complex-number-objects" title="Permalink to this headline">¶</a></h1> <p id="index-0">Python’s complex number objects are implemented as two distinct types when viewed from the C API: one is the Python object exposed to Python programs, and the other is a C structure which represents the actual complex number value. The API provides functions for working with both.</p> <div class="section" id="complex-numbers-as-c-structures"> <h2>Complex Numbers as C Structures<a class="headerlink" href="#complex-numbers-as-c-structures" title="Permalink to this headline">¶</a></h2> <p>Note that the functions which accept these structures as parameters and return them as results do so <em>by value</em> rather than dereferencing them through pointers. This is consistent throughout the API.</p> <dl class="type"> <dt id="c.Py_complex"> <code class="descname">Py_complex</code><a class="headerlink" href="#c.Py_complex" title="Permalink to this definition">¶</a></dt> <dd><p>The C structure which corresponds to the value portion of a Python complex number object. Most of the functions for dealing with complex number objects use structures of this type as input or output values, as appropriate. It is defined as:</p> <div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="k">typedef</span> <span class="k">struct</span> <span class="p">{</span> <span class="kt">double</span> <span class="n">real</span><span class="p">;</span> <span class="kt">double</span> <span class="n">imag</span><span class="p">;</span> <span class="p">}</span> <span class="n">Py_complex</span><span class="p">;</span> </pre></div> </div> </dd></dl> <dl class="function"> <dt id="c._Py_c_sum"> <a class="reference internal" href="#c.Py_complex" title="Py_complex">Py_complex</a> <code class="descname">_Py_c_sum</code><span class="sig-paren">(</span><a class="reference internal" href="#c.Py_complex" title="Py_complex">Py_complex</a><em> left</em>, <a class="reference internal" href="#c.Py_complex" title="Py_complex">Py_complex</a><em> right</em><span class="sig-paren">)</span><a class="headerlink" href="#c._Py_c_sum" title="Permalink to this definition">¶</a></dt> <dd><p>Return the sum of two complex numbers, using the C <a class="reference internal" href="#c.Py_complex" title="Py_complex"><code class="xref c c-type docutils literal notranslate"><span class="pre">Py_complex</span></code></a> representation.</p> </dd></dl> <dl class="function"> <dt id="c._Py_c_diff"> <a class="reference internal" href="#c.Py_complex" title="Py_complex">Py_complex</a> <code class="descname">_Py_c_diff</code><span class="sig-paren">(</span><a class="reference internal" href="#c.Py_complex" title="Py_complex">Py_complex</a><em> left</em>, <a class="reference internal" href="#c.Py_complex" title="Py_complex">Py_complex</a><em> right</em><span class="sig-paren">)</span><a class="headerlink" href="#c._Py_c_diff" title="Permalink to this definition">¶</a></dt> <dd><p>Return the difference between two complex numbers, using the C <a class="reference internal" href="#c.Py_complex" title="Py_complex"><code class="xref c c-type docutils literal notranslate"><span class="pre">Py_complex</span></code></a> representation.</p> </dd></dl> <dl class="function"> <dt id="c._Py_c_neg"> <a class="reference internal" href="#c.Py_complex" title="Py_complex">Py_complex</a> <code class="descname">_Py_c_neg</code><span class="sig-paren">(</span><a class="reference internal" href="#c.Py_complex" title="Py_complex">Py_complex</a><em> complex</em><span class="sig-paren">)</span><a class="headerlink" href="#c._Py_c_neg" title="Permalink to this definition">¶</a></dt> <dd><p>Return the negation of the complex number <em>complex</em>, using the C <a class="reference internal" href="#c.Py_complex" title="Py_complex"><code class="xref c c-type docutils literal notranslate"><span class="pre">Py_complex</span></code></a> representation.</p> </dd></dl> <dl class="function"> <dt id="c._Py_c_prod"> <a class="reference internal" href="#c.Py_complex" title="Py_complex">Py_complex</a> <code class="descname">_Py_c_prod</code><span class="sig-paren">(</span><a class="reference internal" href="#c.Py_complex" title="Py_complex">Py_complex</a><em> left</em>, <a class="reference internal" href="#c.Py_complex" title="Py_complex">Py_complex</a><em> right</em><span class="sig-paren">)</span><a class="headerlink" href="#c._Py_c_prod" title="Permalink to this definition">¶</a></dt> <dd><p>Return the product of two complex numbers, using the C <a class="reference internal" href="#c.Py_complex" title="Py_complex"><code class="xref c c-type docutils literal notranslate"><span class="pre">Py_complex</span></code></a> representation.</p> </dd></dl> <dl class="function"> <dt id="c._Py_c_quot"> <a class="reference internal" href="#c.Py_complex" title="Py_complex">Py_complex</a> <code class="descname">_Py_c_quot</code><span class="sig-paren">(</span><a class="reference internal" href="#c.Py_complex" title="Py_complex">Py_complex</a><em> dividend</em>, <a class="reference internal" href="#c.Py_complex" title="Py_complex">Py_complex</a><em> divisor</em><span class="sig-paren">)</span><a class="headerlink" href="#c._Py_c_quot" title="Permalink to this definition">¶</a></dt> <dd><p>Return the quotient of two complex numbers, using the C <a class="reference internal" href="#c.Py_complex" title="Py_complex"><code class="xref c c-type docutils literal notranslate"><span class="pre">Py_complex</span></code></a> representation.</p> <p>If <em>divisor</em> is null, this method returns zero and sets <code class="xref c c-data docutils literal notranslate"><span class="pre">errno</span></code> to <code class="xref c c-data docutils literal notranslate"><span class="pre">EDOM</span></code>.</p> </dd></dl> <dl class="function"> <dt id="c._Py_c_pow"> <a class="reference internal" href="#c.Py_complex" title="Py_complex">Py_complex</a> <code class="descname">_Py_c_pow</code><span class="sig-paren">(</span><a class="reference internal" href="#c.Py_complex" title="Py_complex">Py_complex</a><em> num</em>, <a class="reference internal" href="#c.Py_complex" title="Py_complex">Py_complex</a><em> exp</em><span class="sig-paren">)</span><a class="headerlink" href="#c._Py_c_pow" title="Permalink to this definition">¶</a></dt> <dd><p>Return the exponentiation of <em>num</em> by <em>exp</em>, using the C <a class="reference internal" href="#c.Py_complex" title="Py_complex"><code class="xref c c-type docutils literal notranslate"><span class="pre">Py_complex</span></code></a> representation.</p> <p>If <em>num</em> is null and <em>exp</em> is not a positive real number, this method returns zero and sets <code class="xref c c-data docutils literal notranslate"><span class="pre">errno</span></code> to <code class="xref c c-data docutils literal notranslate"><span class="pre">EDOM</span></code>.</p> </dd></dl> </div> <div class="section" id="complex-numbers-as-python-objects"> <h2>Complex Numbers as Python Objects<a class="headerlink" href="#complex-numbers-as-python-objects" title="Permalink to this headline">¶</a></h2> <dl class="type"> <dt id="c.PyComplexObject"> <code class="descname">PyComplexObject</code><a class="headerlink" href="#c.PyComplexObject" title="Permalink to this definition">¶</a></dt> <dd><p>This subtype of <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyObject</span></code></a> represents a Python complex number object.</p> </dd></dl> <dl class="var"> <dt id="c.PyComplex_Type"> <a class="reference internal" href="type.html#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a> <code class="descname">PyComplex_Type</code><a class="headerlink" href="#c.PyComplex_Type" title="Permalink to this definition">¶</a></dt> <dd><p>This instance of <a class="reference internal" href="type.html#c.PyTypeObject" title="PyTypeObject"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyTypeObject</span></code></a> represents the Python complex number type. It is the same object as <a class="reference internal" href="../library/functions.html#complex" title="complex"><code class="xref py py-class docutils literal notranslate"><span class="pre">complex</span></code></a> in the Python layer.</p> </dd></dl> <dl class="function"> <dt id="c.PyComplex_Check"> int <code class="descname">PyComplex_Check</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *p</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyComplex_Check" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if its argument is a <a class="reference internal" href="#c.PyComplexObject" title="PyComplexObject"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyComplexObject</span></code></a> or a subtype of <a class="reference internal" href="#c.PyComplexObject" title="PyComplexObject"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyComplexObject</span></code></a>.</p> </dd></dl> <dl class="function"> <dt id="c.PyComplex_CheckExact"> int <code class="descname">PyComplex_CheckExact</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *p</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyComplex_CheckExact" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if its argument is a <a class="reference internal" href="#c.PyComplexObject" title="PyComplexObject"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyComplexObject</span></code></a>, but not a subtype of <a class="reference internal" href="#c.PyComplexObject" title="PyComplexObject"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyComplexObject</span></code></a>.</p> </dd></dl> <dl class="function"> <dt id="c.PyComplex_FromCComplex"> <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="descname">PyComplex_FromCComplex</code><span class="sig-paren">(</span><a class="reference internal" href="#c.Py_complex" title="Py_complex">Py_complex</a><em> v</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyComplex_FromCComplex" title="Permalink to this definition">¶</a></dt> <dd><em class="refcount">Return value: New reference.</em><p>Create a new Python complex number object from a C <a class="reference internal" href="#c.Py_complex" title="Py_complex"><code class="xref c c-type docutils literal notranslate"><span class="pre">Py_complex</span></code></a> value.</p> </dd></dl> <dl class="function"> <dt id="c.PyComplex_FromDoubles"> <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="descname">PyComplex_FromDoubles</code><span class="sig-paren">(</span>double<em> real</em>, double<em> imag</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyComplex_FromDoubles" title="Permalink to this definition">¶</a></dt> <dd><em class="refcount">Return value: New reference.</em><p>Return a new <a class="reference internal" href="#c.PyComplexObject" title="PyComplexObject"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyComplexObject</span></code></a> object from <em>real</em> and <em>imag</em>.</p> </dd></dl> <dl class="function"> <dt id="c.PyComplex_RealAsDouble"> double <code class="descname">PyComplex_RealAsDouble</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *op</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyComplex_RealAsDouble" title="Permalink to this definition">¶</a></dt> <dd><p>Return the real part of <em>op</em> as a C <code class="xref c c-type docutils literal notranslate"><span class="pre">double</span></code>.</p> </dd></dl> <dl class="function"> <dt id="c.PyComplex_ImagAsDouble"> double <code class="descname">PyComplex_ImagAsDouble</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *op</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyComplex_ImagAsDouble" title="Permalink to this definition">¶</a></dt> <dd><p>Return the imaginary part of <em>op</em> as a C <code class="xref c c-type docutils literal notranslate"><span class="pre">double</span></code>.</p> </dd></dl> <dl class="function"> <dt id="c.PyComplex_AsCComplex"> <a class="reference internal" href="#c.Py_complex" title="Py_complex">Py_complex</a> <code class="descname">PyComplex_AsCComplex</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *op</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyComplex_AsCComplex" title="Permalink to this definition">¶</a></dt> <dd><p>Return the <a class="reference internal" href="#c.Py_complex" title="Py_complex"><code class="xref c c-type docutils literal notranslate"><span class="pre">Py_complex</span></code></a> value of the complex number <em>op</em>.</p> <p>If <em>op</em> is not a Python complex number object but has a <a class="reference internal" href="../reference/datamodel.html#object.__complex__" title="object.__complex__"><code class="xref py py-meth docutils literal notranslate"><span class="pre">__complex__()</span></code></a> method, this method will first be called to convert <em>op</em> to a Python complex number object. Upon failure, this method returns <code class="docutils literal notranslate"><span class="pre">-1.0</span></code> as a real value.</p> </dd></dl> </div> </div> </div> </div> </div> <div class="sphinxsidebar" role="navigation" aria-label="main navigation"> <div class="sphinxsidebarwrapper"> <h3><a href="../contents.html">Table of Contents</a></h3> <ul> <li><a class="reference internal" href="#">Complex Number Objects</a><ul> <li><a class="reference internal" href="#complex-numbers-as-c-structures">Complex Numbers as C Structures</a></li> <li><a class="reference internal" href="#complex-numbers-as-python-objects">Complex Numbers as Python Objects</a></li> </ul> </li> </ul> <h4>Previous topic</h4> <p class="topless"><a href="float.html" title="previous chapter">Floating Point Objects</a></p> <h4>Next topic</h4> <p class="topless"><a href="bytes.html" title="next chapter">Bytes Objects</a></p> <div role="note" aria-label="source link"> <h3>This Page</h3> <ul class="this-page-menu"> <li><a href="../bugs.html">Report a Bug</a></li> <li> <a href="https://github.com/python/cpython/blob/3.7/Doc/c-api/complex.rst" rel="nofollow">Show Source </a> </li> </ul> </div> </div> </div> <div class="clearer"></div> </div> <div class="related" role="navigation" aria-label="related navigation"> <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="bytes.html" title="Bytes Objects" >next</a> |</li> <li class="right" > <a href="float.html" title="Floating Point Objects" >previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="https://www.python.org/">Python</a> »</li> <li> <span class="language_switcher_placeholder">en</span> <span class="version_switcher_placeholder">3.7.4</span> <a href="../index.html">Documentation </a> » </li> <li class="nav-item nav-item-1"><a href="index.html" >Python/C API Reference Manual</a> »</li> <li class="nav-item nav-item-2"><a href="concrete.html" >Concrete Objects Layer</a> »</li> <li class="right"> <div class="inline-search" style="display: none" role="search"> <form class="inline-search" action="../search.html" method="get"> <input placeholder="Quick search" type="text" name="q" /> <input type="submit" value="Go" /> <input type="hidden" name="check_keywords" value="yes" /> <input type="hidden" name="area" value="default" /> </form> </div> <script type="text/javascript">$('.inline-search').show(0);</script> | </li> </ul> </div> <div class="footer"> © <a href="../copyright.html">Copyright</a> 2001-2019, Python Software Foundation. <br /> The Python Software Foundation is a non-profit corporation. <a href="https://www.python.org/psf/donations/">Please donate.</a> <br /> Last updated on Jul 13, 2019. <a href="../bugs.html">Found a bug</a>? <br /> Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 2.0.1. </div> </body> </html>