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<title>6.13 The global statement </title>
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<H1><A NAME="SECTION0081300000000000000000"></A><A NAME="global"></A>
<BR>
6.13 The <tt class="keyword">global</tt> statement
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    <td><a id='tok-global_stmt' xml:id='tok-global_stmt'>global_stmt</a></td>
    <td>::=</td>
    <td>"global" <a class='grammartoken' href="identifiers.html#tok-identifier">identifier</a> ("," <a class='grammartoken' href="identifiers.html#tok-identifier">identifier</a>)*</td></tr>
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<P>
The <tt class="keyword">global</tt> statement is a declaration which holds for the
entire current code block.  It means that the listed identifiers are to be
interpreted as globals.  It would be impossible to assign to a global
variable without <tt class="keyword">global</tt>, although free variables may refer
to globals without being declared global.
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<P>
Names listed in a <tt class="keyword">global</tt> statement must not be used in the same
code block textually preceding that <tt class="keyword">global</tt> statement.

<P>
Names listed in a <tt class="keyword">global</tt> statement must not be defined as formal
parameters or in a <tt class="keyword">for</tt> loop control target, <tt class="keyword">class</tt>
definition, function definition, or <tt class="keyword">import</tt> statement.

<P>
(The current implementation does not enforce the latter two
restrictions, but programs should not abuse this freedom, as future
implementations may enforce them or silently change the meaning of the
program.)

<P>
<strong>Programmer's note:</strong>
the <tt class="keyword">global</tt> is a directive to the parser.  It
applies only to code parsed at the same time as the <tt class="keyword">global</tt>
statement.  In particular, a <tt class="keyword">global</tt> statement contained in an
<tt class="keyword">exec</tt> statement does not affect the code block <em>containing</em>
the <tt class="keyword">exec</tt> statement, and code contained in an <tt class="keyword">exec</tt>
statement is unaffected by <tt class="keyword">global</tt> statements in the code
containing the <tt class="keyword">exec</tt> statement.  The same applies to the
<tt class="function">eval()</tt>, <tt class="function">execfile()</tt> and <tt class="function">compile()</tt> functions.
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<span class="release-info">Release 2.4.2, documentation updated on 28 September 2005.</span>
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