how to replace the characters of the list in python -

i want write code in python replace every every small letter character "a" , every capital letter "a" , every digit 0. write code caused error of x not in list, code below

tokens = ["apple","banana","orange", "pineapple", "10nuts"] token in tokens:     ch in token:         if ch.islower():             loc = tokens.index(ch)             tokens.remove(ch)             tokens.insert(loc,'a');         elif ch.isupper():             loc = tokens.index(ch)             tokens.remove(ch)             tokens.insert(loc,'a');         elif ch.isdigit():             loc = tokens.index(ch)             tokens.remove(ch)             tokens.insert(loc,'0'); t in tokens:     print t 

you should use regular expressions perform task:

import re  tokens = ["apple","banana","orange", "pineapple", "10nuts"]  upper = re.compile(r"[a-z]") lower = re.compile(r"[a-z]") number = re.compile(r"[0-9]")  token in tokens:     token = re.sub(upper,'a',token)     token = re.sub(lower,'a',token)     token = re.sub(number,'0',token)     print token 

the variables upper, lower , number precompiled regular expressions, since using them in loop, faster.

you shorten down loop 1 3 lines:

for token in tokens:     token = re.sub(upper,'a',re.sub(lower,'a',re.sub(number,'0',token)))     print token 

hope helps

edit: took code above, one-liner, used enumeration loop suggested pzp1997:

import re  tokens = ["apple","banana","orange", "pineapple", "10nuts"]  upper = re.compile(r"[a-z]") lower = re.compile(r"[a-z]") number = re.compile(r"[0-9]")  i, token in enumerate(tokens):     tokens[i] = re.sub(upper,'a',re.sub(lower,'a',re.sub(number,'0',token)))  print tokens