ommit letters.txt

#Given a non-empty string and an int n, return a new string where the char at index n has been removed. The value of n will be a valid index of a char in the original string (i.e. n will be in the range 0..len(str)-1 inclusive).
missing_char('kitten', 1) ? 'ktten'
missing_char('kitten', 0) ? 'itten'
missing_char('kitten', 4) ? 'kittn'


def missing_char(str, n):
  front = str[:n]
  back = str[n+1:]
  return front + back