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<H1><A NAME="SECTION007700000000000000000"></A><A NAME="shifting"></A>
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5.7 Shifting operations
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<P>
The shifting operations have lower priority than the arithmetic
operations:

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    <td><a id='tok-shift_expr' xml:id='tok-shift_expr'>shift_expr</a></td>
    <td>::=</td>
    <td><a class='grammartoken' href="binary.html#tok-a_expr">a_expr</a>
              | <a class='grammartoken' href="shifting.html#tok-shift_expr">shift_expr</a> ( "&lt;&lt;" | "&gt;&gt;" ) <a class='grammartoken' href="binary.html#tok-a_expr">a_expr</a></td></tr>
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<P>
These operators accept plain or long integers as arguments.  The
arguments are converted to a common type.  They shift the first
argument to the left or right by the number of bits given by the
second argument.

<P>
A right shift by <var>n</var> bits is defined as division by
<code>pow(2,<var>n</var>)</code>.  A left shift by <var>n</var> bits is defined as
multiplication with <code>pow(2,<var>n</var>)</code>; for plain integers there is
no overflow check so in that case the operation drops bits and flips
the sign if the result is not less than <code>pow(2,31)</code> in absolute
value.  Negative shift counts raise a <tt class="exception">ValueError</tt>
exception.
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<span class="release-info">Release 2.4.2, documentation updated on 28 September 2005.</span>
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