| 1 | <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> |
| 2 | <html> |
| 3 | <head> |
| 4 | <link rel="STYLESHEET" href="api.css" type='text/css' /> |
| 5 | <link rel="SHORTCUT ICON" href="../icons/pyfav.png" type="image/png" /> |
| 6 | <link rel='start' href='../index.html' title='Python Documentation Index' /> |
| 7 | <link rel="first" href="api.html" title='Python/C API Reference Manual' /> |
| 8 | <link rel='contents' href='contents.html' title="Contents" /> |
| 9 | <link rel='index' href='genindex.html' title='Index' /> |
| 10 | <link rel='last' href='about.html' title='About this document...' /> |
| 11 | <link rel='help' href='about.html' title='About this document...' /> |
| 12 | <link rel="prev" href="typeObjects.html" /> |
| 13 | <link rel="parent" href="fundamental.html" /> |
| 14 | <link rel="next" href="numericObjects.html" /> |
| 15 | <meta name='aesop' content='information' /> |
| 16 | <title>7.1.2 The None Object </title> |
| 17 | </head> |
| 18 | <body> |
| 19 | <DIV CLASS="navigation"> |
| 20 | <div id='top-navigation-panel' xml:id='top-navigation-panel'> |
| 21 | <table align="center" width="100%" cellpadding="0" cellspacing="2"> |
| 22 | <tr> |
| 23 | <td class='online-navigation'><a rel="prev" title="7.1.1 Type Objects" |
| 24 | href="typeObjects.html"><img src='../icons/previous.png' |
| 25 | border='0' height='32' alt='Previous Page' width='32' /></A></td> |
| 26 | <td class='online-navigation'><a rel="parent" title="7.1 Fundamental Objects" |
| 27 | href="fundamental.html"><img src='../icons/up.png' |
| 28 | border='0' height='32' alt='Up One Level' width='32' /></A></td> |
| 29 | <td class='online-navigation'><a rel="next" title="7.2 Numeric Objects" |
| 30 | href="numericObjects.html"><img src='../icons/next.png' |
| 31 | border='0' height='32' alt='Next Page' width='32' /></A></td> |
| 32 | <td align="center" width="100%">Python/C API Reference Manual</td> |
| 33 | <td class='online-navigation'><a rel="contents" title="Table of Contents" |
| 34 | href="contents.html"><img src='../icons/contents.png' |
| 35 | border='0' height='32' alt='Contents' width='32' /></A></td> |
| 36 | <td class='online-navigation'><img src='../icons/blank.png' |
| 37 | border='0' height='32' alt='' width='32' /></td> |
| 38 | <td class='online-navigation'><a rel="index" title="Index" |
| 39 | href="genindex.html"><img src='../icons/index.png' |
| 40 | border='0' height='32' alt='Index' width='32' /></A></td> |
| 41 | </tr></table> |
| 42 | <div class='online-navigation'> |
| 43 | <b class="navlabel">Previous:</b> |
| 44 | <a class="sectref" rel="prev" href="typeObjects.html">7.1.1 Type Objects</A> |
| 45 | <b class="navlabel">Up:</b> |
| 46 | <a class="sectref" rel="parent" href="fundamental.html">7.1 Fundamental Objects</A> |
| 47 | <b class="navlabel">Next:</b> |
| 48 | <a class="sectref" rel="next" href="numericObjects.html">7.2 Numeric Objects</A> |
| 49 | </div> |
| 50 | <hr /></div> |
| 51 | </DIV> |
| 52 | <!--End of Navigation Panel--> |
| 53 | |
| 54 | <H2><A NAME="SECTION009120000000000000000"></A><A NAME="noneObject"></A> |
| 55 | <BR> |
| 56 | 7.1.2 The None Object |
| 57 | </H2> |
| 58 | |
| 59 | <P> |
| 60 | <a id='l2h-365' xml:id='l2h-365'></a>Note that the <tt class="ctype">PyTypeObject</tt> for <code>None</code> is not directly |
| 61 | exposed in the Python/C API. Since <code>None</code> is a singleton, |
| 62 | testing for object identity (using "<tt class="samp">==</tt>" in C) is sufficient. |
| 63 | There is no <tt class="cfunction">PyNone_Check()</tt> function for the same reason. |
| 64 | |
| 65 | <P> |
| 66 | <dl><dt>PyObject* <b><tt id='l2h-366' xml:id='l2h-366' class="cdata">Py_None</tt></b></dt> |
| 67 | <dd> |
| 68 | The Python <code>None</code> object, denoting lack of value. This object |
| 69 | has no methods. It needs to be treated just like any other object |
| 70 | with respect to reference counts. |
| 71 | </dd></dl> |
| 72 | |
| 73 | <P> |
| 74 | <dl><dt><b><tt id='l2h-367' xml:id='l2h-367' class="macro">Py_RETURN_NONE</tt></b></dt> |
| 75 | <dd> |
| 76 | Properly handle returning <tt class="cdata">Py_None</tt> from within a C function. |
| 77 | </dl> |
| 78 | |
| 79 | <P> |
| 80 | |
| 81 | <DIV CLASS="navigation"> |
| 82 | <div class='online-navigation'> |
| 83 | <p></p><hr /> |
| 84 | <table align="center" width="100%" cellpadding="0" cellspacing="2"> |
| 85 | <tr> |
| 86 | <td class='online-navigation'><a rel="prev" title="7.1.1 Type Objects" |
| 87 | href="typeObjects.html"><img src='../icons/previous.png' |
| 88 | border='0' height='32' alt='Previous Page' width='32' /></A></td> |
| 89 | <td class='online-navigation'><a rel="parent" title="7.1 Fundamental Objects" |
| 90 | href="fundamental.html"><img src='../icons/up.png' |
| 91 | border='0' height='32' alt='Up One Level' width='32' /></A></td> |
| 92 | <td class='online-navigation'><a rel="next" title="7.2 Numeric Objects" |
| 93 | href="numericObjects.html"><img src='../icons/next.png' |
| 94 | border='0' height='32' alt='Next Page' width='32' /></A></td> |
| 95 | <td align="center" width="100%">Python/C API Reference Manual</td> |
| 96 | <td class='online-navigation'><a rel="contents" title="Table of Contents" |
| 97 | href="contents.html"><img src='../icons/contents.png' |
| 98 | border='0' height='32' alt='Contents' width='32' /></A></td> |
| 99 | <td class='online-navigation'><img src='../icons/blank.png' |
| 100 | border='0' height='32' alt='' width='32' /></td> |
| 101 | <td class='online-navigation'><a rel="index" title="Index" |
| 102 | href="genindex.html"><img src='../icons/index.png' |
| 103 | border='0' height='32' alt='Index' width='32' /></A></td> |
| 104 | </tr></table> |
| 105 | <div class='online-navigation'> |
| 106 | <b class="navlabel">Previous:</b> |
| 107 | <a class="sectref" rel="prev" href="typeObjects.html">7.1.1 Type Objects</A> |
| 108 | <b class="navlabel">Up:</b> |
| 109 | <a class="sectref" rel="parent" href="fundamental.html">7.1 Fundamental Objects</A> |
| 110 | <b class="navlabel">Next:</b> |
| 111 | <a class="sectref" rel="next" href="numericObjects.html">7.2 Numeric Objects</A> |
| 112 | </div> |
| 113 | </div> |
| 114 | <hr /> |
| 115 | <span class="release-info">Release 2.4.2, documentation updated on 28 September 2005.</span> |
| 116 | </DIV> |
| 117 | <!--End of Navigation Panel--> |
| 118 | <ADDRESS> |
| 119 | See <i><a href="about.html">About this document...</a></i> for information on suggesting changes. |
| 120 | </ADDRESS> |
| 121 | </BODY> |
| 122 | </HTML> |