bpo-29710: Clarify documentation for Bitwise binary operation (GH-1691) · python/cpython@8764a6f (original) (raw)
`@@ -382,7 +382,7 @@ modules.
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`.. _bitstring-ops:
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`Bitwise Operations on Integer Types
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`-
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`.. index::
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` triple: operations on; integer; types
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`@@ -396,9 +396,9 @@ Bitwise Operations on Integer Types
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` operator: >>
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` operator: ~
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Bitwise operations only make sense for integers. Negative numbers are treated
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as their 2's complement value (this assumes that there are enough bits so that
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no overflow occurs during the operation).
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Bitwise operations only make sense for integers. The result of bitwise
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operations is calculated as though carried out in two's complement with an
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infinite number of sign bits.
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`The priorities of the binary bitwise operations are all lower than the numeric
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``` operations and higher than the comparisons; the unary operation ~ has the
`@@ -409,13 +409,13 @@ This table lists the bitwise operations sorted in ascending priority:
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`+------------+--------------------------------+----------+
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`| Operation | Result | Notes |
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`+============+================================+==========+
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``` -
| ``x | y`` | bitwise :dfn:`or` of *x* and | |
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| ``x | y`` | bitwise :dfn:`or` of *x* and | (4) |
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`| | y | |
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`+------------+--------------------------------+----------+
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| ``x ^ y`` | bitwise :dfn:`exclusive or` of | |
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| ``x ^ y`` | bitwise :dfn:`exclusive or` of | (4) |
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`| | x and y | |
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`+------------+--------------------------------+----------+
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| ``x & y`` | bitwise :dfn:`and` of *x* and | |
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| ``x & y`` | bitwise :dfn:`and` of *x* and | (4) |
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`| | y | |
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`+------------+--------------------------------+----------+
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``` | x << n | x shifted left by n bits | (1)(2) |
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``` A right shift by *n* bits is equivalent to division by ``pow(2, n)`` without
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` overflow check.
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(4)
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Performing these calculations with at least one extra sign extension bit in
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a finite two's complement representation (a working bit-width of
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``1 + max(x.bit_length(), y.bit_length()`` or more) is sufficient to get the
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same result as if there were an infinite number of sign bits.
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`Additional Methods on Integer Types
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`-----------------------------------
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