| 1 | <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> |
| 2 | <html> |
| 3 | <head> |
| 4 | <link rel="STYLESHEET" href="ref.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="ref.html" title='Python 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="next" href="literals.html" /> |
| 13 | <link rel="prev" href="other-tokens.html" /> |
| 14 | <link rel="parent" href="lexical.html" /> |
| 15 | <link rel="next" href="keywords.html" /> |
| 16 | <meta name='aesop' content='information' /> |
| 17 | <title>2.3 Identifiers and keywords</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="2.2 Other tokens" |
| 25 | href="other-tokens.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="2. Lexical analysis" |
| 28 | href="lexical.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="2.3.1 Keywords" |
| 31 | href="keywords.html"><img src='../icons/next.png' |
| 32 | border='0' height='32' alt='Next Page' width='32' /></A></td> |
| 33 | <td align="center" width="100%">Python Reference Manual</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'><a rel="index" title="Index" |
| 40 | href="genindex.html"><img src='../icons/index.png' |
| 41 | border='0' height='32' alt='Index' width='32' /></A></td> |
| 42 | </tr></table> |
| 43 | <div class='online-navigation'> |
| 44 | <b class="navlabel">Previous:</b> |
| 45 | <a class="sectref" rel="prev" href="other-tokens.html">2.2 Other tokens</A> |
| 46 | <b class="navlabel">Up:</b> |
| 47 | <a class="sectref" rel="parent" href="lexical.html">2. Lexical analysis</A> |
| 48 | <b class="navlabel">Next:</b> |
| 49 | <a class="sectref" rel="next" href="keywords.html">2.3.1 Keywords</A> |
| 50 | </div> |
| 51 | <hr /></div> |
| 52 | </DIV> |
| 53 | <!--End of Navigation Panel--> |
| 54 | |
| 55 | <H1><A NAME="SECTION004300000000000000000"></A><A NAME="identifiers"></A><a id='l2h-10' xml:id='l2h-10'></a> |
| 56 | <BR> |
| 57 | 2.3 Identifiers and keywords |
| 58 | </H1> |
| 59 | |
| 60 | <P> |
| 61 | Identifiers (also referred to as <em>names</em>) are described by the following |
| 62 | lexical definitions: |
| 63 | |
| 64 | <P> |
| 65 | <dl><dd class="grammar"> |
| 66 | <div class="productions"> |
| 67 | <table> |
| 68 | <tr> |
| 69 | <td><a id='tok-identifier' xml:id='tok-identifier'>identifier</a></td> |
| 70 | <td>::=</td> |
| 71 | <td>(<a class='grammartoken' href="identifiers.html#tok-letter">letter</a>|"_") (<a class='grammartoken' href="identifiers.html#tok-letter">letter</a> | <a class='grammartoken' href="identifiers.html#tok-digit">digit</a> | "_")*</td></tr> |
| 72 | <tr> |
| 73 | <td><a id='tok-letter' xml:id='tok-letter'>letter</a></td> |
| 74 | <td>::=</td> |
| 75 | <td><a class='grammartoken' href="identifiers.html#tok-lowercase">lowercase</a> | <a class='grammartoken' href="identifiers.html#tok-uppercase">uppercase</a></td></tr> |
| 76 | <tr> |
| 77 | <td><a id='tok-lowercase' xml:id='tok-lowercase'>lowercase</a></td> |
| 78 | <td>::=</td> |
| 79 | <td>"a"..."z"</td></tr> |
| 80 | <tr> |
| 81 | <td><a id='tok-uppercase' xml:id='tok-uppercase'>uppercase</a></td> |
| 82 | <td>::=</td> |
| 83 | <td>"A"..."Z"</td></tr> |
| 84 | <tr> |
| 85 | <td><a id='tok-digit' xml:id='tok-digit'>digit</a></td> |
| 86 | <td>::=</td> |
| 87 | <td>"0"..."9"</td></tr> |
| 88 | </table> |
| 89 | </div> |
| 90 | <a class="grammar-footer" |
| 91 | href="grammar.txt" type="text/plain" |
| 92 | >Download entire grammar as text.</a> |
| 93 | </dd></dl> |
| 94 | |
| 95 | <P> |
| 96 | Identifiers are unlimited in length. Case is significant. |
| 97 | |
| 98 | <P> |
| 99 | |
| 100 | <p><br /></p><hr class='online-navigation' /> |
| 101 | <div class='online-navigation'> |
| 102 | <!--Table of Child-Links--> |
| 103 | <A NAME="CHILD_LINKS"><STRONG>Subsections</STRONG></a> |
| 104 | |
| 105 | <UL CLASS="ChildLinks"> |
| 106 | <LI><A href="keywords.html">2.3.1 Keywords</a> |
| 107 | <LI><A href="id-classes.html">2.3.2 Reserved classes of identifiers</a> |
| 108 | </ul> |
| 109 | <!--End of Table of Child-Links--> |
| 110 | </div> |
| 111 | |
| 112 | <DIV CLASS="navigation"> |
| 113 | <div class='online-navigation'> |
| 114 | <p></p><hr /> |
| 115 | <table align="center" width="100%" cellpadding="0" cellspacing="2"> |
| 116 | <tr> |
| 117 | <td class='online-navigation'><a rel="prev" title="2.2 Other tokens" |
| 118 | href="other-tokens.html"><img src='../icons/previous.png' |
| 119 | border='0' height='32' alt='Previous Page' width='32' /></A></td> |
| 120 | <td class='online-navigation'><a rel="parent" title="2. Lexical analysis" |
| 121 | href="lexical.html"><img src='../icons/up.png' |
| 122 | border='0' height='32' alt='Up One Level' width='32' /></A></td> |
| 123 | <td class='online-navigation'><a rel="next" title="2.3.1 Keywords" |
| 124 | href="keywords.html"><img src='../icons/next.png' |
| 125 | border='0' height='32' alt='Next Page' width='32' /></A></td> |
| 126 | <td align="center" width="100%">Python Reference Manual</td> |
| 127 | <td class='online-navigation'><a rel="contents" title="Table of Contents" |
| 128 | href="contents.html"><img src='../icons/contents.png' |
| 129 | border='0' height='32' alt='Contents' width='32' /></A></td> |
| 130 | <td class='online-navigation'><img src='../icons/blank.png' |
| 131 | border='0' height='32' alt='' width='32' /></td> |
| 132 | <td class='online-navigation'><a rel="index" title="Index" |
| 133 | href="genindex.html"><img src='../icons/index.png' |
| 134 | border='0' height='32' alt='Index' width='32' /></A></td> |
| 135 | </tr></table> |
| 136 | <div class='online-navigation'> |
| 137 | <b class="navlabel">Previous:</b> |
| 138 | <a class="sectref" rel="prev" href="other-tokens.html">2.2 Other tokens</A> |
| 139 | <b class="navlabel">Up:</b> |
| 140 | <a class="sectref" rel="parent" href="lexical.html">2. Lexical analysis</A> |
| 141 | <b class="navlabel">Next:</b> |
| 142 | <a class="sectref" rel="next" href="keywords.html">2.3.1 Keywords</A> |
| 143 | </div> |
| 144 | </div> |
| 145 | <hr /> |
| 146 | <span class="release-info">Release 2.4.2, documentation updated on 28 September 2005.</span> |
| 147 | </DIV> |
| 148 | <!--End of Navigation Panel--> |
| 149 | <ADDRESS> |
| 150 | See <i><a href="about.html">About this document...</a></i> for information on suggesting changes. |
| 151 | </ADDRESS> |
| 152 | </BODY> |
| 153 | </HTML> |