You can use or at last study difflib from Python's stdlib to write your code.
It is very flexible, and has algorithms to find differences between lists of strings, and to point these differences. Then you can use the get_close_matches() to find similar words:
>>> get_close_matches('appel', ['ape', 'apple', 'peach', 'puppy'])
['apple', 'ape']
It is not the solution but maybe it is a start.
