Find the position of difference between two strings

Question

I have two strings of equal length, how can I find all the locations where the strings are different?

For example, \"HELPMEPLZ\" and \"HELPNEPLX\" are different at p

Answer 1

Try this:

s1 = 'HELPMEPLZ'
s2 = 'HELPNEPLX'
[i for i in xrange(len(s1)) if s1[i] != s2[i]]

It will return:

> [4, 8]

The above solution will return a list with the indexes in sorted order, won't create any unnecessary intermediate data structures and it will work on Python 2.3 - 2.7. For Python 3.x replace xrange for range.