XORing long strings opimization?

[Peter Otten]

Noen wrote:

> def XOR(s1,s2):
> """ XOR string s1 with s2 """
> output = ""
> # Argument check
> if (type(s1) and type(s2)) != type(""):
> raise TypeError, "Arguments are not strings"
> if len(s1) != len(s2):
> raise ValueError, "Size differs in strings"
> # Xoring
> for c1 in s1:
> for c2 in s2:
> output += chr(ord(c1) ^ ord(c2))
> return output
> 
> This way is very slow for large strings.
> Anyone know of a better and faster way to do it?

Before we start optimizing:

len(XOR(s1, s2)) == len(s1) * len(s2)

Bug or feature?

Peter