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<title>6.13 The global statement
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<H1><A NAME=
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"global"></A>
6.13 The
<tt class=
"keyword">global
</tt> statement
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<td>"global" <a class='grammartoken'
href=
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</a> (
"," <a class='grammartoken'
href=
"identifiers.html#tok-identifier">identifier
</a>)*
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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.
<a id='l2h-
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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.
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.
(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
<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=
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2005.
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