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<H2><A NAME="SECTION004320000000000000000"></A><A NAME="id-classes"></A>
<BR>
2.3.2 Reserved classes of identifiers
</H2>
<P>
Certain classes of identifiers (besides keywords) have special
meanings. These classes are identified by the patterns of leading and
trailing underscore characters:
<P>
<DL>
<DT><STRONG><code>_*</code></STRONG></DT>
<DD>Not imported by "<tt class="samp">from <var>module</var> import *</tt>". The special
identifier "<tt class="samp">_</tt>" is used in the interactive interpreter to store
the result of the last evaluation; it is stored in the
<tt class="module">__builtin__</tt> module. When not in interactive mode, "<tt class="samp">_</tt>" has no special meaning and is not defined.
See section <A href="import.html#import">6.12</A>, ``The <tt class="keyword">import</tt> statement.''
<P>
<span class="note"><b class="label">Note:</b>
The name "<tt class="samp">_</tt>" is often used in conjunction with
internationalization; refer to the documentation for the
<a class="ulink" href="../lib/module-gettext.html"
><tt class="module">gettext</tt> module</a> for more
information on this convention.</span>
<P>
</DD>
<DT><STRONG><code>__*__</code></STRONG></DT>
<DD>System-defined names. These names are defined by the interpreter
and its implementation (including the standard library);
applications should not expect to define additional names using this
convention. The set of names of this class defined by Python may be
extended in future versions.
See section <A href="specialnames.html#specialnames">3.3</A>, ``Special method names.''
<P>
</DD>
<DT><STRONG><code>__*</code></STRONG></DT>
<DD>Class-private names. Names in this category, when used within the
context of a class definition, are re-written to use a mangled form
to help avoid name clashes between ``private'' attributes of base
and derived classes.
See section <A href="atom-identifiers.html#atom-identifiers">5.2.1</A>, ``Identifiers (Names).''
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<span class="release-info">Release 2.4.3, documentation updated on 29 March 2006.</span>
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