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<h3>Files</h3>
<p>The built-in function <tT CLAss="monofont">open(</tt><I><TT Class="monofont">name</TT></I>
<Tt class="monofont"> [,</tt><i><tt class="monofont">mode</tt></i>
<tT clAss="monofont">])</tT> opens and creates files, as shown here:</p>
<pre>
f = open('foo') # Opens 'foo' for reading
f = open('foo','w') # Open for writing </Pre>
<p>The file mode is <TT CLass="monofont">'r'</tT> for read, <TT Class="monofont">'w'</TT> for write, or <TT clasS="monofont">'a'</TT> for append. The mode character can be followed by <Tt class="monofont">'b'</tt> for binary data, such as <tt class="monofont">'rb'</tt> or <tt cLasS="monofont">'wb'</tt>. This is optional on UNIX, but required on Windows, and should be included if you抮e concerned about portability. In addition, a file can be opened for updates by supplying a plus (<tT clasS="monofont">+</tt>) character, such as <tT CLAss="monofont">'r+'</tt> or <TT CLass="monofont">'w+'</tT>. When a file is opened for update, you can perform both input and output, as long as all output operations flush their data before any subsequent input operations. If a file is opened using <TT Class="monofont">'w+'</TT> mode, its length is first truncated to zero.</P>
<P><tt class="monofont">open()</tt> returns a file object that supports the methods shown in <a href="92#2.html">Table 9.1</a>.</p>
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