Each Answer to this Q is separated by one/two green lines.
'a' instead of
'b'? I’m using Python 3.
The keys used are the ordinals of the characters, not the characters themselves:
It’s easier to use
>>> 'a'.translate(str.maketrans('a', 'b')) 'b' >>> help(str.translate) Help on method_descriptor: translate(...) S.translate(table) -> str Return a copy of the string S, where all characters have been mapped through the given translation table, which must be a mapping of Unicode ordinals to Unicode ordinals, strings, or None. Unmapped characters are left untouched. Characters mapped to None are deleted.