问题
Is there an easy way to produce a one's complement in python?
For instance, if you take the hex value 0x9E
, I need to convert it to 0x61
.
I need to swap the binary 1's for 0's and 0's for 1's. It feels like this should be simple.
回答1:
Just use the XOR operator ^ against 0xFF:
>>> hex(0x9E ^ 0xFF)
'0x61'
If you need to work with values larger than a byte, you could create the mask from the int.bit_length() method on your value:
>>> value = 0x9E
>>> mask = (1 << value.bit_length()) - 1
>>> hex(value ^ mask)
'0x61'
>>> value = 0x9E9E
>>> mask = (1 << value.bit_length()) - 1
>>> hex(value ^ mask)
'0x6161'
回答2:
Hah. just found out that python bin()
return a string!
so we can have some fun at this!
for x in numbers: # numbers is a list of int
b = bin(x)
#print b # e.g. String 0b1011100101
b = b.replace('0', 'x')
b = b.replace('1', '0')
b = b.replace('x', '1')
b = b.replace('1b', '0b')
#print b # String 0b0100011010
print int(b, 2) # the decimal representation
来源:https://stackoverflow.com/questions/13492826/from-hexadecimal-to-ones-complement-in-python