<!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta charset="utf-8" /> <title>MemoryView 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="Weak Reference Objects" href="weakref.html" /> <link rel="prev" title="Slice Objects" href="slice.html" /> <link rel="shortcut icon" type="image/png" href="../_static/py.png" /> <link rel="canonical" href="https://docs.python.org/3/c-api/memoryview.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="weakref.html" title="Weak Reference Objects" accesskey="N">next</a> |</li> <li class="right" > <a href="slice.html" title="Slice 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"> <span class="target" id="memoryview-objects"></span><div class="section" id="index-0"> <span id="id1"></span><h1>MemoryView objects<a class="headerlink" href="#index-0" title="Permalink to this headline">¶</a></h1> <p>A <a class="reference internal" href="../library/stdtypes.html#memoryview" title="memoryview"><code class="xref py py-class docutils literal notranslate"><span class="pre">memoryview</span></code></a> object exposes the C level <a class="reference internal" href="buffer.html#bufferobjects"><span class="std std-ref">buffer interface</span></a> as a Python object which can then be passed around like any other object.</p> <dl class="function"> <dt id="c.PyMemoryView_FromObject"> <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a> *<code class="descname">PyMemoryView_FromObject</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *obj</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyMemoryView_FromObject" title="Permalink to this definition">¶</a></dt> <dd><em class="refcount">Return value: New reference.</em><p>Create a memoryview object from an object that provides the buffer interface. If <em>obj</em> supports writable buffer exports, the memoryview object will be read/write, otherwise it may be either read-only or read/write at the discretion of the exporter.</p> </dd></dl> <dl class="function"> <dt id="c.PyMemoryView_FromMemory"> <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a> *<code class="descname">PyMemoryView_FromMemory</code><span class="sig-paren">(</span>char<em> *mem</em>, Py_ssize_t<em> size</em>, int<em> flags</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyMemoryView_FromMemory" title="Permalink to this definition">¶</a></dt> <dd><em class="refcount">Return value: New reference.</em><p>Create a memoryview object using <em>mem</em> as the underlying buffer. <em>flags</em> can be one of <code class="xref c c-macro docutils literal notranslate"><span class="pre">PyBUF_READ</span></code> or <code class="xref c c-macro docutils literal notranslate"><span class="pre">PyBUF_WRITE</span></code>.</p> <div class="versionadded"> <p><span class="versionmodified added">New in version 3.3.</span></p> </div> </dd></dl> <dl class="function"> <dt id="c.PyMemoryView_FromBuffer"> <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a> *<code class="descname">PyMemoryView_FromBuffer</code><span class="sig-paren">(</span><a class="reference internal" href="buffer.html#c.Py_buffer" title="Py_buffer">Py_buffer</a><em> *view</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyMemoryView_FromBuffer" title="Permalink to this definition">¶</a></dt> <dd><em class="refcount">Return value: New reference.</em><p>Create a memoryview object wrapping the given buffer structure <em>view</em>. For simple byte buffers, <a class="reference internal" href="#c.PyMemoryView_FromMemory" title="PyMemoryView_FromMemory"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyMemoryView_FromMemory()</span></code></a> is the preferred function.</p> </dd></dl> <dl class="function"> <dt id="c.PyMemoryView_GetContiguous"> <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a> *<code class="descname">PyMemoryView_GetContiguous</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *obj</em>, int<em> buffertype</em>, char<em> order</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyMemoryView_GetContiguous" title="Permalink to this definition">¶</a></dt> <dd><em class="refcount">Return value: New reference.</em><p>Create a memoryview object to a <a class="reference internal" href="../glossary.html#term-contiguous"><span class="xref std std-term">contiguous</span></a> chunk of memory (in either ‘C’ or ‘F’ortran <em>order</em>) from an object that defines the buffer interface. If memory is contiguous, the memoryview object points to the original memory. Otherwise, a copy is made and the memoryview points to a new bytes object.</p> </dd></dl> <dl class="function"> <dt id="c.PyMemoryView_Check"> int <code class="descname">PyMemoryView_Check</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *obj</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyMemoryView_Check" title="Permalink to this definition">¶</a></dt> <dd><p>Return true if the object <em>obj</em> is a memoryview object. It is not currently allowed to create subclasses of <a class="reference internal" href="../library/stdtypes.html#memoryview" title="memoryview"><code class="xref py py-class docutils literal notranslate"><span class="pre">memoryview</span></code></a>.</p> </dd></dl> <dl class="function"> <dt id="c.PyMemoryView_GET_BUFFER"> <a class="reference internal" href="buffer.html#c.Py_buffer" title="Py_buffer">Py_buffer</a> *<code class="descname">PyMemoryView_GET_BUFFER</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *mview</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyMemoryView_GET_BUFFER" title="Permalink to this definition">¶</a></dt> <dd><p>Return a pointer to the memoryview’s private copy of the exporter’s buffer. <em>mview</em> <strong>must</strong> be a memoryview instance; this macro doesn’t check its type, you must do it yourself or you will risk crashes.</p> </dd></dl> <dl class="function"> <dt id="c.PyMemoryView_GET_BASE"> <a class="reference internal" href="buffer.html#c.Py_buffer" title="Py_buffer">Py_buffer</a> *<code class="descname">PyMemoryView_GET_BASE</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *mview</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyMemoryView_GET_BASE" title="Permalink to this definition">¶</a></dt> <dd><p>Return either a pointer to the exporting object that the memoryview is based on or <em>NULL</em> if the memoryview has been created by one of the functions <a class="reference internal" href="#c.PyMemoryView_FromMemory" title="PyMemoryView_FromMemory"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyMemoryView_FromMemory()</span></code></a> or <a class="reference internal" href="#c.PyMemoryView_FromBuffer" title="PyMemoryView_FromBuffer"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyMemoryView_FromBuffer()</span></code></a>. <em>mview</em> <strong>must</strong> be a memoryview instance.</p> </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="slice.html" title="previous chapter">Slice Objects</a></p> <h4>Next topic</h4> <p class="topless"><a href="weakref.html" title="next chapter">Weak Reference 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/memoryview.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="weakref.html" title="Weak Reference Objects" >next</a> |</li> <li class="right" > <a href="slice.html" title="Slice 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>