Replace every nth letter in a string

Question

I\'m writing a function to replace every n-th letter from a string

def replaceN(str, n):
   for i in range(len(str)):
     n=str[i]
     newStr=str.replace(         


        

Answer 1

Another option, using re:

import re
def repl(matchobj):
    return re.sub('.$','*',matchobj.group(0))
def replaceN(str, n):
    return re.sub('.'*n,repl,str)

However, this needs additional library. If you have this library already imported, this may be a shorthand method.