Multiple string.replace()

I'm trying to search and replace words in a long string in FIOC.


(pseudocode)
for i between 0 and 10:
  str = str.replace(words[i], replacements[i])

However, since strings are immutable, the string is copied each time and is slow. Since the length of the words are exactly the same as the replacements, I would like to edit the original string directly. Is that possible somehow?

>>2
Oops.  Since you want to replace the words, change the second part to:
for old_word,new_word in zip(words,replacements):
    i = str.index(old_word)
    str[i] = new_word
  
also str in this case is the list of words