projects / OpenSPARC-T2-SAM / blame
| Commit | Line | Data |
|---|---|---|
| 920dae64 AT |
1 | <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> |
| 2 | <html> | |
| 3 | <head> | |
| 4 | <link rel="STYLESHEET" href="ext.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="ext.html" title='Extending and Embedding the Python Interpreter' /> | |
| 8 | <link rel='contents' href='contents.html' title="Contents" /> | |
| 9 | <link rel='last' href='about.html' title='About this document...' /> | |
| 10 | <link rel='help' href='about.html' title='About this document...' /> | |
| 11 | <link rel="next" href="refcounts.html" /> | |
| 12 | <link rel="prev" href="parseTupleAndKeywords.html" /> | |
| 13 | <link rel="parent" href="intro.html" /> | |
| 14 | <link rel="next" href="refcounts.html" /> | |
| 15 | <meta name='aesop' content='information' /> | |
| 16 | <title>1.9 Building Arbitrary Values | |
| 17 | </title> | |
| 18 | </head> | |
| 19 | <body> | |
| 20 | <DIV CLASS="navigation"> | |
| 21 | <div id='top-navigation-panel' xml:id='top-navigation-panel'> | |
| 22 | <table align="center" width="100%" cellpadding="0" cellspacing="2"> | |
| 23 | <tr> | |
| 24 | <td class='online-navigation'><a rel="prev" title="1.8 Keyword Parameters for" | |
| 25 | href="parseTupleAndKeywords.html"><img src='../icons/previous.png' | |
| 26 | border='0' height='32' alt='Previous Page' width='32' /></A></td> | |
| 27 | <td class='online-navigation'><a rel="parent" title="1. Extending Python with" | |
| 28 | href="intro.html"><img src='../icons/up.png' | |
| 29 | border='0' height='32' alt='Up One Level' width='32' /></A></td> | |
| 30 | <td class='online-navigation'><a rel="next" title="1.10 Reference Counts" | |
| 31 | href="refcounts.html"><img src='../icons/next.png' | |
| 32 | border='0' height='32' alt='Next Page' width='32' /></A></td> | |
| 33 | <td align="center" width="100%">Extending and Embedding the Python Interpreter</td> | |
| 34 | <td class='online-navigation'><a rel="contents" title="Table of Contents" | |
| 35 | href="contents.html"><img src='../icons/contents.png' | |
| 36 | border='0' height='32' alt='Contents' width='32' /></A></td> | |
| 37 | <td class='online-navigation'><img src='../icons/blank.png' | |
| 38 | border='0' height='32' alt='' width='32' /></td> | |
| 39 | <td class='online-navigation'><img src='../icons/blank.png' | |
| 40 | border='0' height='32' alt='' width='32' /></td> | |
| 41 | </tr></table> | |
| 42 | <div class='online-navigation'> | |
| 43 | <b class="navlabel">Previous:</b> | |
| 44 | <a class="sectref" rel="prev" href="parseTupleAndKeywords.html">1.8 Keyword Parameters for</A> | |
| 45 | <b class="navlabel">Up:</b> | |
| 46 | <a class="sectref" rel="parent" href="intro.html">1. Extending Python with</A> | |
| 47 | <b class="navlabel">Next:</b> | |
| 48 | <a class="sectref" rel="next" href="refcounts.html">1.10 Reference Counts</A> | |
| 49 | </div> | |
| 50 | <hr /></div> | |
| 51 | </DIV> | |
| 52 | <!--End of Navigation Panel--> | |
| 53 | ||
| 54 | <H1><A NAME="SECTION003900000000000000000"></A><A NAME="buildValue"></A> | |
| 55 | <BR> | |
| 56 | 1.9 Building Arbitrary Values | |
| 57 | ||
| 58 | </H1> | |
| 59 | ||
| 60 | <P> | |
| 61 | This function is the counterpart to <tt class="cfunction">PyArg_ParseTuple()</tt>. It is | |
| 62 | declared as follows: | |
| 63 | ||
| 64 | <P> | |
| 65 | <div class="verbatim"><pre> | |
| 66 | PyObject *Py_BuildValue(char *format, ...); | |
| 67 | </pre></div> | |
| 68 | ||
| 69 | <P> | |
| 70 | It recognizes a set of format units similar to the ones recognized by | |
| 71 | <tt class="cfunction">PyArg_ParseTuple()</tt>, but the arguments (which are input to the | |
| 72 | function, not output) must not be pointers, just values. It returns a | |
| 73 | new Python object, suitable for returning from a C function called | |
| 74 | from Python. | |
| 75 | ||
| 76 | <P> | |
| 77 | One difference with <tt class="cfunction">PyArg_ParseTuple()</tt>: while the latter | |
| 78 | requires its first argument to be a tuple (since Python argument lists | |
| 79 | are always represented as tuples internally), | |
| 80 | <tt class="cfunction">Py_BuildValue()</tt> does not always build a tuple. It builds | |
| 81 | a tuple only if its format string contains two or more format units. | |
| 82 | If the format string is empty, it returns <code>None</code>; if it contains | |
| 83 | exactly one format unit, it returns whatever object is described by | |
| 84 | that format unit. To force it to return a tuple of size 0 or one, | |
| 85 | parenthesize the format string. | |
| 86 | ||
| 87 | <P> | |
| 88 | Examples (to the left the call, to the right the resulting Python value): | |
| 89 | ||
| 90 | <P> | |
| 91 | <div class="verbatim"><pre> | |
| 92 | Py_BuildValue("") None | |
| 93 | Py_BuildValue("i", 123) 123 | |
| 94 | Py_BuildValue("iii", 123, 456, 789) (123, 456, 789) | |
| 95 | Py_BuildValue("s", "hello") 'hello' | |
| 96 | Py_BuildValue("ss", "hello", "world") ('hello', 'world') | |
| 97 | Py_BuildValue("s#", "hello", 4) 'hell' | |
| 98 | Py_BuildValue("()") () | |
| 99 | Py_BuildValue("(i)", 123) (123,) | |
| 100 | Py_BuildValue("(ii)", 123, 456) (123, 456) | |
| 101 | Py_BuildValue("(i,i)", 123, 456) (123, 456) | |
| 102 | Py_BuildValue("[i,i]", 123, 456) [123, 456] | |
| 103 | Py_BuildValue("{s:i,s:i}", | |
| 104 | "abc", 123, "def", 456) {'abc': 123, 'def': 456} | |
| 105 | Py_BuildValue("((ii)(ii)) (ii)", | |
| 106 | 1, 2, 3, 4, 5, 6) (((1, 2), (3, 4)), (5, 6)) | |
| 107 | </pre></div> | |
| 108 | ||
| 109 | <P> | |
| 110 | ||
| 111 | <DIV CLASS="navigation"> | |
| 112 | <div class='online-navigation'> | |
| 113 | <p></p><hr /> | |
| 114 | <table align="center" width="100%" cellpadding="0" cellspacing="2"> | |
| 115 | <tr> | |
| 116 | <td class='online-navigation'><a rel="prev" title="1.8 Keyword Parameters for" | |
| 117 | href="parseTupleAndKeywords.html"><img src='../icons/previous.png' | |
| 118 | border='0' height='32' alt='Previous Page' width='32' /></A></td> | |
| 119 | <td class='online-navigation'><a rel="parent" title="1. Extending Python with" | |
| 120 | href="intro.html"><img src='../icons/up.png' | |
| 121 | border='0' height='32' alt='Up One Level' width='32' /></A></td> | |
| 122 | <td class='online-navigation'><a rel="next" title="1.10 Reference Counts" | |
| 123 | href="refcounts.html"><img src='../icons/next.png' | |
| 124 | border='0' height='32' alt='Next Page' width='32' /></A></td> | |
| 125 | <td align="center" width="100%">Extending and Embedding the Python Interpreter</td> | |
| 126 | <td class='online-navigation'><a rel="contents" title="Table of Contents" | |
| 127 | href="contents.html"><img src='../icons/contents.png' | |
| 128 | border='0' height='32' alt='Contents' width='32' /></A></td> | |
| 129 | <td class='online-navigation'><img src='../icons/blank.png' | |
| 130 | border='0' height='32' alt='' width='32' /></td> | |
| 131 | <td class='online-navigation'><img src='../icons/blank.png' | |
| 132 | border='0' height='32' alt='' width='32' /></td> | |
| 133 | </tr></table> | |
| 134 | <div class='online-navigation'> | |
| 135 | <b class="navlabel">Previous:</b> | |
| 136 | <a class="sectref" rel="prev" href="parseTupleAndKeywords.html">1.8 Keyword Parameters for</A> | |
| 137 | <b class="navlabel">Up:</b> | |
| 138 | <a class="sectref" rel="parent" href="intro.html">1. Extending Python with</A> | |
| 139 | <b class="navlabel">Next:</b> | |
| 140 | <a class="sectref" rel="next" href="refcounts.html">1.10 Reference Counts</A> | |
| 141 | </div> | |
| 142 | </div> | |
| 143 | <hr /> | |
| 144 | <span class="release-info">Release 2.4.2, documentation updated on 28 September 2005.</span> | |
| 145 | </DIV> | |
| 146 | <!--End of Navigation Panel--> | |
| 147 | <ADDRESS> | |
| 148 | See <i><a href="about.html">About this document...</a></i> for information on suggesting changes. | |
| 149 | </ADDRESS> | |
| 150 | </BODY> | |
| 151 | </HTML> |