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="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="imaginary.html" /> | |
13 | <link rel="prev" href="integers.html" /> | |
14 | <link rel="parent" href="literals.html" /> | |
15 | <link rel="next" href="imaginary.html" /> | |
16 | <meta name='aesop' content='information' /> | |
17 | <title>2.4.5 Floating point literals</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="2.4.4 Integer and long" | |
25 | href="integers.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="2.4 Literals" | |
28 | href="literals.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="2.4.6 Imaginary literals" | |
31 | href="imaginary.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="integers.html">2.4.4 Integer and long</A> | |
46 | <b class="navlabel">Up:</b> | |
47 | <a class="sectref" rel="parent" href="literals.html">2.4 Literals</A> | |
48 | <b class="navlabel">Next:</b> | |
49 | <a class="sectref" rel="next" href="imaginary.html">2.4.6 Imaginary literals</A> | |
50 | </div> | |
51 | <hr /></div> | |
52 | </DIV> | |
53 | <!--End of Navigation Panel--> | |
54 | ||
55 | <H2><A NAME="SECTION004450000000000000000"></A><A NAME="floating"></A> | |
56 | <BR> | |
57 | 2.4.5 Floating point literals | |
58 | </H2> | |
59 | ||
60 | <P> | |
61 | Floating point literals are described by the following lexical | |
62 | definitions: | |
63 | ||
64 | <P> | |
65 | <dl><dd class="grammar"> | |
66 | <div class="productions"> | |
67 | <table> | |
68 | <tr> | |
69 | <td><a id='tok-floatnumber' xml:id='tok-floatnumber'>floatnumber</a></td> | |
70 | <td>::=</td> | |
71 | <td><a class='grammartoken' href="floating.html#tok-pointfloat">pointfloat</a> | <a class='grammartoken' href="floating.html#tok-exponentfloat">exponentfloat</a></td></tr> | |
72 | <tr> | |
73 | <td><a id='tok-pointfloat' xml:id='tok-pointfloat'>pointfloat</a></td> | |
74 | <td>::=</td> | |
75 | <td>[<a class='grammartoken' href="floating.html#tok-intpart">intpart</a>] <a class='grammartoken' href="floating.html#tok-fraction">fraction</a> | <a class='grammartoken' href="floating.html#tok-intpart">intpart</a> "."</td></tr> | |
76 | <tr> | |
77 | <td><a id='tok-exponentfloat' xml:id='tok-exponentfloat'>exponentfloat</a></td> | |
78 | <td>::=</td> | |
79 | <td>(<a class='grammartoken' href="floating.html#tok-intpart">intpart</a> | <a class='grammartoken' href="floating.html#tok-pointfloat">pointfloat</a>) | |
80 | <a class='grammartoken' href="floating.html#tok-exponent">exponent</a></td></tr> | |
81 | <tr> | |
82 | <td><a id='tok-intpart' xml:id='tok-intpart'>intpart</a></td> | |
83 | <td>::=</td> | |
84 | <td><a class='grammartoken' href="identifiers.html#tok-digit">digit</a>+</td></tr> | |
85 | <tr> | |
86 | <td><a id='tok-fraction' xml:id='tok-fraction'>fraction</a></td> | |
87 | <td>::=</td> | |
88 | <td>"." <a class='grammartoken' href="identifiers.html#tok-digit">digit</a>+</td></tr> | |
89 | <tr> | |
90 | <td><a id='tok-exponent' xml:id='tok-exponent'>exponent</a></td> | |
91 | <td>::=</td> | |
92 | <td>("e" | "E") ["+" | "-"] <a class='grammartoken' href="identifiers.html#tok-digit">digit</a>+</td></tr> | |
93 | </table> | |
94 | </div> | |
95 | <a class="grammar-footer" | |
96 | href="grammar.txt" type="text/plain" | |
97 | >Download entire grammar as text.</a> | |
98 | </dd></dl> | |
99 | ||
100 | <P> | |
101 | Note that the integer and exponent parts of floating point numbers | |
102 | can look like octal integers, but are interpreted using radix 10. For | |
103 | example, "<tt class="samp">077e010</tt>" is legal, and denotes the same number | |
104 | as "<tt class="samp">77e10</tt>". | |
105 | The allowed range of floating point literals is | |
106 | implementation-dependent. | |
107 | Some examples of floating point literals: | |
108 | ||
109 | <P> | |
110 | <div class="verbatim"><pre> | |
111 | 3.14 10. .001 1e100 3.14e-10 0e0 | |
112 | </pre></div> | |
113 | ||
114 | <P> | |
115 | Note that numeric literals do not include a sign; a phrase like | |
116 | <code>-1</code> is actually an expression composed of the operator | |
117 | <code>-</code> and the literal <code>1</code>. | |
118 | ||
119 | <P> | |
120 | ||
121 | <DIV CLASS="navigation"> | |
122 | <div class='online-navigation'> | |
123 | <p></p><hr /> | |
124 | <table align="center" width="100%" cellpadding="0" cellspacing="2"> | |
125 | <tr> | |
126 | <td class='online-navigation'><a rel="prev" title="2.4.4 Integer and long" | |
127 | href="integers.html"><img src='../icons/previous.png' | |
128 | border='0' height='32' alt='Previous Page' width='32' /></A></td> | |
129 | <td class='online-navigation'><a rel="parent" title="2.4 Literals" | |
130 | href="literals.html"><img src='../icons/up.png' | |
131 | border='0' height='32' alt='Up One Level' width='32' /></A></td> | |
132 | <td class='online-navigation'><a rel="next" title="2.4.6 Imaginary literals" | |
133 | href="imaginary.html"><img src='../icons/next.png' | |
134 | border='0' height='32' alt='Next Page' width='32' /></A></td> | |
135 | <td align="center" width="100%">Python Reference Manual</td> | |
136 | <td class='online-navigation'><a rel="contents" title="Table of Contents" | |
137 | href="contents.html"><img src='../icons/contents.png' | |
138 | border='0' height='32' alt='Contents' width='32' /></A></td> | |
139 | <td class='online-navigation'><img src='../icons/blank.png' | |
140 | border='0' height='32' alt='' width='32' /></td> | |
141 | <td class='online-navigation'><a rel="index" title="Index" | |
142 | href="genindex.html"><img src='../icons/index.png' | |
143 | border='0' height='32' alt='Index' width='32' /></A></td> | |
144 | </tr></table> | |
145 | <div class='online-navigation'> | |
146 | <b class="navlabel">Previous:</b> | |
147 | <a class="sectref" rel="prev" href="integers.html">2.4.4 Integer and long</A> | |
148 | <b class="navlabel">Up:</b> | |
149 | <a class="sectref" rel="parent" href="literals.html">2.4 Literals</A> | |
150 | <b class="navlabel">Next:</b> | |
151 | <a class="sectref" rel="next" href="imaginary.html">2.4.6 Imaginary literals</A> | |
152 | </div> | |
153 | </div> | |
154 | <hr /> | |
155 | <span class="release-info">Release 2.4.2, documentation updated on 28 September 2005.</span> | |
156 | </DIV> | |
157 | <!--End of Navigation Panel--> | |
158 | <ADDRESS> | |
159 | See <i><a href="about.html">About this document...</a></i> for information on suggesting changes. | |
160 | </ADDRESS> | |
161 | </BODY> | |
162 | </HTML> |