python check if bit in sequence is true or false

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Chapters
00:00 Question
00:29 Accepted answer (Score 22)
01:06 Answer 2 (Score 11)
01:25 Answer 3 (Score 5)
01:38 Answer 4 (Score 4)
01:48 Thank you

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Full question
https://stackoverflow.com/questions/2859...

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Content licensed under CC BY-SA
https://meta.stackexchange.com/help/lice...

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Tags
#python #bit

#avk47

ACCEPTED ANSWER

Score 23

Without the bit shifting:

if bits & 0b1000:
    ...

EDIT: Actually, (1 << 3) is optimized out by the compiler.

>>> dis.dis(lambda x: x & (1 << 3))
  1           0 LOAD_FAST                0 (x)
              3 LOAD_CONST               3 (8)
              6 BINARY_AND          
              7 RETURN_VALUE        
>>> dis.dis(lambda x: x & 0b1000)
  1           0 LOAD_FAST                0 (x)
              3 LOAD_CONST               1 (8)
              6 BINARY_AND          
              7 RETURN_VALUE

The two solutions are equivalent, choose the one that looks more readable in your context.

ANSWER 2

Score 5

You can use bit shifting

>>> 0b10010101 >> 4 & 1
1
>>> 0b10010101 >> 3 & 1
0

ANSWER 3

Score 4

bits = 0b11010011

if bits & (1 << 3):
    ...

ANSWER 4

Score 2

bits = '1110111'

if bits[-4] == '0':
    print "......false"
else:
    print  "....true"