Pattern Matching Given # of Characters and no String Input; use RegularExpressions?

[tiissa]

tiissa wrote:
> If you know the number of characters to match can't you just compare 
> slices?
If you don't, you can still do it by hand:

In [7]: def cmp(s1,s2):
   ....:     diff_map=[chr(s1[i]!=s2[i]) for i in range(min(len(s1), 
len(s2)))]
   ....:     diff_index=''.join(diff_map).find(chr(True))
   ....:     if -1==diff_index:
   ....:         return min(len(s1), len(s2))
   ....:     else:
   ....:         return diff_index
   ....:

In [8]: cmp('cccat','cccap')
Out[8]: 4

In [9]: cmp('ccc','cccap')
Out[9]: 3

In [10]: cmp('cccat','dddfa')
Out[10]: 0