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<H3><A NAME="SECTION004141000000000000000"></A>
<BR>
2.1.4.1 Bit-string Operations on Integer Types 
</H3>

<P>
Plain and long integer types support additional operations that make
sense only for bit-strings.  Negative numbers are treated as their 2's
complement value (for long integers, this assumes a sufficiently large
number of bits that no overflow occurs during the operation).

<P>
The priorities of the binary bit-wise operations are all lower than
the numeric operations and higher than the comparisons; the unary
operation "<tt class=samp>~</tt>" has the same priority as the other unary numeric
operations ("<tt class=samp>+</tt>" and "<tt class=samp>-</tt>").

<P>
This table lists the bit-string operations sorted in ascending
priority (operations in the same box have the same priority):

<P>
<table border align=center>
  <thead>
    <tr bgcolor="#99CCFF">
      <th><b>Operation</b></th>
      <th align=left><b>Result</b></th>
      <th><b>Notes</b></th>
    </thead>
  <tbody valign=baseline>
    <tr><td align=center valign=baseline><code><var>x</var> | <var>y</var></code></td>
        <td>bitwise <i class=dfn>or</i> of <var>x</var> and <var>y</var></td>
        <td align=center>&nbsp;</td>
    <tr><td align=center valign=baseline><code><var>x</var> ^ <var>y</var></code></td>
        <td>bitwise <i class=dfn>exclusive or</i> of <var>x</var> and <var>y</var></td>
        <td align=center>&nbsp;</td>
    <tr><td align=center valign=baseline><code><var>x</var> &amp; <var>y</var></code></td>
        <td>bitwise <i class=dfn>and</i> of <var>x</var> and <var>y</var></td>
        <td align=center>&nbsp;</td>
    <tr><td align=center valign=baseline><code><var>x</var> &lt;&lt; <var>n</var></code></td>
        <td><var>x</var> shifted left by <var>n</var> bits</td>
        <td align=center>(1), (2)&nbsp;</td>
    <tr><td align=center valign=baseline><code><var>x</var> &gt;&gt; <var>n</var></code></td>
        <td><var>x</var> shifted right by <var>n</var> bits</td>
        <td align=center>(1), (3)&nbsp;</td>
  
    <tr><td align=center valign=baseline><code>~<var>x</var></code></td>
        <td>the bits of <var>x</var> inverted</td>
        <td align=center>&nbsp;</td></tbody>
</table>
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<P>
Notes:
<DL>
<DT><STRONG>(1)</STRONG>
<DD>Negative shift counts are illegal and cause a
<tt class=exception>ValueError</tt> to be raised.
<DT><STRONG>(2)</STRONG>
<DD>A left shift by <var>n</var> bits is equivalent to
multiplication by <tt>pow(2, <var>n</var>)</tt> without overflow check.
<DT><STRONG>(3)</STRONG>
<DD>A right shift by <var>n</var> bits is equivalent to
division by <tt>pow(2, <var>n</var>)</tt> without overflow check.
</DL>

<P>
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