Add single bit manipulation operations. (#3284)

* Add single bit manipuation operations.

* fixup! Add single bit manipuation operations.

* Change wording.
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Phil Bazun 2020-10-25 10:24:35 +01:00 committed by GitHub
parent 3a191d9a7c
commit 1b5c1b8344
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#!/usr/bin/env python3
"""Provide the functionality to manipulate a single bit."""
def set_bit(number: int, position: int):
"""
Set the bit at position to 1.
Details: perform bitwise or for given number and X.
Where X is a number with all the bits zeroes and bit on given
position one.
>>> set_bit(0b1101, 1) # 0b1111
15
>>> set_bit(0b0, 5) # 0b100000
32
>>> set_bit(0b1111, 1) # 0b1111
15
"""
return number | (1 << position)
def clear_bit(number: int, position: int):
"""
Set the bit at position to 0.
Details: perform bitwise and for given number and X.
Where X is a number with all the bits ones and bit on given
position zero.
>>> clear_bit(0b10010, 1) # 0b10000
16
>>> clear_bit(0b0, 5) # 0b0
0
"""
return number & ~(1 << position)
def flip_bit(number: int, position: int):
"""
Flip the bit at position.
Details: perform bitwise xor for given number and X.
Where X is a number with all the bits zeroes and bit on given
position one.
>>> flip_bit(0b101, 1) # 0b111
7
>>> flip_bit(0b101, 0) # 0b100
4
"""
return number ^ (1 << position)
def is_bit_set(number: int, position: int) -> bool:
"""
Is the bit at position set?
Details: Shift the bit at position to be the first (smallest) bit.
Then check if the first bit is set by anding the shifted number with 1.
>>> is_bit_set(0b1010, 0)
False
>>> is_bit_set(0b1010, 1)
True
>>> is_bit_set(0b1010, 2)
False
>>> is_bit_set(0b1010, 3)
True
>>> is_bit_set(0b0, 17)
False
"""
return ((number >> position) & 1) == 1
if __name__ == "__main__":
import doctest
doctest.testmod()