Hamming distance between two binary strings not working

Hyperion picture Hyperion · Jun 23, 2015 · Viewed 27.6k times · Source

I found an interesting algorithm to calculate hamming distance on this site:

def hamming2(x,y):
    """Calculate the Hamming distance between two bit strings"""
    assert len(x) == len(y)
    count,z = 0,x^y
    while z:
        count += 1
        z &= z-1 # magic!
    return count

The point is that this algorithm only works on bit strings and I'm trying to compare two strings that are binary but they are in string format, like

'100010'
'101000'

How can I make them work with this algorithm?

Answer

dlask picture dlask · Jun 23, 2015

Implement it:

def hamming2(s1, s2):
    """Calculate the Hamming distance between two bit strings"""
    assert len(s1) == len(s2)
    return sum(c1 != c2 for c1, c2 in zip(s1, s2))

And test it:

assert hamming2("1010", "1111") == 2
assert hamming2("1111", "0000") == 4
assert hamming2("1111", "1111") == 0