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

I like Eric's answer, but you indicated in the comment that the first letter shouldn't be replaced. You can adapt the code like this then:

''.join("*" if i % n == 0 else char for i, char in enumerate(string, 1))
                                             the difference is here  ^

def replaceN(s, n):
    return ''.join(
      '*' if not i%n else char for i, char in enumerate(s, 1))

>>> replaceN('welcome', 3)
'we*co*e'