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(python2.1-lib.info)Bit-string Operations

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Bit-string Operations on Integer Types
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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).

The priorities of the binary bit-wise operations are all lower than the
numeric operations and higher than the comparisons; the unary operation
`~' has the same priority as the other unary numeric operations (`+'
and `-').

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

Operation                Result                   Notes
------                   -----                    -----
X | Y                    bitwise "or" of X and Y  
X ^{} Y                  bitwise "exclusive or"   
                         of X and Y               
X &{} Y                  bitwise "and" of X and   
                         Y                        
X << N                   X shifted left by N      (1), (2)
                         bits                     
X >> N                   X shifted right by N     (1), (3)
                         bits                     
~X                       the bits of X inverted   

Notes:
`(1)'
     Negative shift counts are illegal and cause a `ValueError' to be
     raised.

`(2)'
     A left shift by N bits is equivalent to multiplication by `pow(2,
     N)' without overflow check.

`(3)'
     A right shift by N bits is equivalent to division by `pow(2, N)'
     without overflow check.