D7net
Home
Console
Upload
information
Create File
Create Folder
About
Tools
:
/
usr
/
share
/
doc
/
python2-docs
/
html
/
c-api
/
Filename :
float.html
back
Copy
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="X-UA-Compatible" content="IE=Edge" /> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Floating Point Objects — Python 2.7.16 documentation</title> <link rel="stylesheet" href="../_static/classic.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/sidebar.js"></script> <link rel="search" type="application/opensearchdescription+xml" title="Search within Python 2.7.16 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="Complex Number Objects" href="complex.html" /> <link rel="prev" title="Long Integer Objects" href="long.html" /> <link rel="shortcut icon" type="image/png" href="../_static/py.png" /> <link rel="canonical" href="https://docs.python.org/2/c-api/float.html" /> <script type="text/javascript" src="../_static/copybutton.js"></script> </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="complex.html" title="Complex Number Objects" accesskey="N">next</a> |</li> <li class="right" > <a href="long.html" title="Long Integer 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> <a href="../index.html">Python 2.7.16 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> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body" role="main"> <div class="section" id="floating-point-objects"> <span id="floatobjects"></span><h1>Floating Point Objects<a class="headerlink" href="#floating-point-objects" title="Permalink to this headline">¶</a></h1> <span class="target" id="index-0"></span><dl class="type"> <dt id="c.PyFloatObject"> <code class="descname">PyFloatObject</code><a class="headerlink" href="#c.PyFloatObject" 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 floating point object.</p> </dd></dl> <dl class="var"> <dt id="c.PyFloat_Type"> <a class="reference internal" href="type.html#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a> <code class="descname">PyFloat_Type</code><a class="headerlink" href="#c.PyFloat_Type" title="Permalink to this definition">¶</a></dt> <dd><p id="index-1">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 floating point type. This is the same object as <code class="docutils literal notranslate"><span class="pre">float</span></code> and <code class="docutils literal notranslate"><span class="pre">types.FloatType</span></code>.</p> </dd></dl> <dl class="function"> <dt id="c.PyFloat_Check"> int <code class="descname">PyFloat_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.PyFloat_Check" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if its argument is a <a class="reference internal" href="#c.PyFloatObject" title="PyFloatObject"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyFloatObject</span></code></a> or a subtype of <a class="reference internal" href="#c.PyFloatObject" title="PyFloatObject"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyFloatObject</span></code></a>.</p> <div class="versionchanged"> <p><span class="versionmodified">Changed in version 2.2: </span>Allowed subtypes to be accepted.</p> </div> </dd></dl> <dl class="function"> <dt id="c.PyFloat_CheckExact"> int <code class="descname">PyFloat_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.PyFloat_CheckExact" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if its argument is a <a class="reference internal" href="#c.PyFloatObject" title="PyFloatObject"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyFloatObject</span></code></a>, but not a subtype of <a class="reference internal" href="#c.PyFloatObject" title="PyFloatObject"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyFloatObject</span></code></a>.</p> <div class="versionadded"> <p><span class="versionmodified">New in version 2.2.</span></p> </div> </dd></dl> <dl class="function"> <dt id="c.PyFloat_FromString"> <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="descname">PyFloat_FromString</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *str</em>, char<em> **pend</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyFloat_FromString" title="Permalink to this definition">¶</a></dt> <dd><em class="refcount">Return value: New reference.</em><p>Create a <a class="reference internal" href="#c.PyFloatObject" title="PyFloatObject"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyFloatObject</span></code></a> object based on the string value in <em>str</em>, or <em>NULL</em> on failure. The <em>pend</em> argument is ignored. It remains only for backward compatibility.</p> </dd></dl> <dl class="function"> <dt id="c.PyFloat_FromDouble"> <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="descname">PyFloat_FromDouble</code><span class="sig-paren">(</span>double<em> v</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyFloat_FromDouble" title="Permalink to this definition">¶</a></dt> <dd><em class="refcount">Return value: New reference.</em><p>Create a <a class="reference internal" href="#c.PyFloatObject" title="PyFloatObject"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyFloatObject</span></code></a> object from <em>v</em>, or <em>NULL</em> on failure.</p> </dd></dl> <dl class="function"> <dt id="c.PyFloat_AsDouble"> double <code class="descname">PyFloat_AsDouble</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *pyfloat</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyFloat_AsDouble" title="Permalink to this definition">¶</a></dt> <dd><p>Return a C <code class="xref c c-type docutils literal notranslate"><span class="pre">double</span></code> representation of the contents of <em>pyfloat</em>. If <em>pyfloat</em> is not a Python floating point object but has a <a class="reference internal" href="../reference/datamodel.html#object.__float__" title="object.__float__"><code class="xref py py-meth docutils literal notranslate"><span class="pre">__float__()</span></code></a> method, this method will first be called to convert <em>pyfloat</em> into a float. This method returns <code class="docutils literal notranslate"><span class="pre">-1.0</span></code> upon failure, so one should call <a class="reference internal" href="exceptions.html#c.PyErr_Occurred" title="PyErr_Occurred"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyErr_Occurred()</span></code></a> to check for errors.</p> </dd></dl> <dl class="function"> <dt id="c.PyFloat_AS_DOUBLE"> double <code class="descname">PyFloat_AS_DOUBLE</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *pyfloat</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyFloat_AS_DOUBLE" title="Permalink to this definition">¶</a></dt> <dd><p>Return a C <code class="xref c c-type docutils literal notranslate"><span class="pre">double</span></code> representation of the contents of <em>pyfloat</em>, but without error checking.</p> </dd></dl> <dl class="function"> <dt id="c.PyFloat_GetInfo"> <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="descname">PyFloat_GetInfo</code><span class="sig-paren">(</span>void<span class="sig-paren">)</span><a class="headerlink" href="#c.PyFloat_GetInfo" title="Permalink to this definition">¶</a></dt> <dd><p>Return a structseq instance which contains information about the precision, minimum and maximum values of a float. It’s a thin wrapper around the header file <code class="file docutils literal notranslate"><span class="pre">float.h</span></code>.</p> <div class="versionadded"> <p><span class="versionmodified">New in version 2.6.</span></p> </div> </dd></dl> <dl class="function"> <dt id="c.PyFloat_GetMax"> double <code class="descname">PyFloat_GetMax</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyFloat_GetMax" title="Permalink to this definition">¶</a></dt> <dd><p>Return the maximum representable finite float <em>DBL_MAX</em> as C <code class="xref c c-type docutils literal notranslate"><span class="pre">double</span></code>.</p> <div class="versionadded"> <p><span class="versionmodified">New in version 2.6.</span></p> </div> </dd></dl> <dl class="function"> <dt id="c.PyFloat_GetMin"> double <code class="descname">PyFloat_GetMin</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyFloat_GetMin" title="Permalink to this definition">¶</a></dt> <dd><p>Return the minimum normalized positive float <em>DBL_MIN</em> as C <code class="xref c c-type docutils literal notranslate"><span class="pre">double</span></code>.</p> <div class="versionadded"> <p><span class="versionmodified">New in version 2.6.</span></p> </div> </dd></dl> <dl class="function"> <dt id="c.PyFloat_ClearFreeList"> int <code class="descname">PyFloat_ClearFreeList</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyFloat_ClearFreeList" title="Permalink to this definition">¶</a></dt> <dd><p>Clear the float free list. Return the number of items that could not be freed.</p> <div class="versionadded"> <p><span class="versionmodified">New in version 2.6.</span></p> </div> </dd></dl> <dl class="function"> <dt id="c.PyFloat_AsString"> void <code class="descname">PyFloat_AsString</code><span class="sig-paren">(</span>char<em> *buf</em>, <a class="reference internal" href="#c.PyFloatObject" title="PyFloatObject">PyFloatObject</a><em> *v</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyFloat_AsString" title="Permalink to this definition">¶</a></dt> <dd><p>Convert the argument <em>v</em> to a string, using the same rules as <a class="reference internal" href="../library/functions.html#str" title="str"><code class="xref py py-func docutils literal notranslate"><span class="pre">str()</span></code></a>. The length of <em>buf</em> should be at least 100.</p> <p>This function is unsafe to call because it writes to a buffer whose length it does not know.</p> <div class="deprecated"> <p><span class="versionmodified">Deprecated since version 2.7: </span>Use <code class="xref py py-func docutils literal notranslate"><span class="pre">PyObject_Str()</span></code> or <code class="xref py py-func docutils literal notranslate"><span class="pre">PyOS_double_to_string()</span></code> instead.</p> </div> </dd></dl> <dl class="function"> <dt id="c.PyFloat_AsReprString"> void <code class="descname">PyFloat_AsReprString</code><span class="sig-paren">(</span>char<em> *buf</em>, <a class="reference internal" href="#c.PyFloatObject" title="PyFloatObject">PyFloatObject</a><em> *v</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyFloat_AsReprString" title="Permalink to this definition">¶</a></dt> <dd><p>Same as PyFloat_AsString, except uses the same rules as <a class="reference internal" href="../library/functions.html#repr" title="repr"><code class="xref py py-func docutils literal notranslate"><span class="pre">repr()</span></code></a>. The length of <em>buf</em> should be at least 100.</p> <p>This function is unsafe to call because it writes to a buffer whose length it does not know.</p> <div class="deprecated"> <p><span class="versionmodified">Deprecated since version 2.7: </span>Use <code class="xref py py-func docutils literal notranslate"><span class="pre">PyObject_Repr()</span></code> or <code class="xref py py-func docutils literal notranslate"><span class="pre">PyOS_double_to_string()</span></code> instead.</p> </div> </dd></dl> </div> </div> </div> </div> <div class="sphinxsidebar" role="navigation" aria-label="main navigation"> <div class="sphinxsidebarwrapper"> <h4>Previous topic</h4> <p class="topless"><a href="long.html" title="previous chapter">Long Integer Objects</a></p> <h4>Next topic</h4> <p class="topless"><a href="complex.html" title="next chapter">Complex Number Objects</a></p> <div role="note" aria-label="source link"> <h3>This Page</h3> <ul class="this-page-menu"> <li><a href="../_sources/c-api/float.rst.txt" rel="nofollow">Show Source</a></li> </ul> </div> <div id="searchbox" style="display: none" role="search"> <h3>Quick search</h3> <div class="searchformwrapper"> <form class="search" action="../search.html" method="get"> <input 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> </div> <script type="text/javascript">$('#searchbox').show(0);</script> </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="complex.html" title="Complex Number Objects" >next</a> |</li> <li class="right" > <a href="long.html" title="Long Integer 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> <a href="../index.html">Python 2.7.16 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> </ul> </div> <div class="footer"> © <a href="../copyright.html">Copyright</a> 1990-2019, 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 Mar 27, 2019. <a href="../bugs.html">Found a bug</a>? <br /> Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 1.7.6. </div> </body> </html>