MIT 6.00 Assignments solution

ps3d.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

from ps3b import subStringMatchExact
from ps3c import subStringMatchOneSub


def subStringMatchExactlyOneSub(target, key):
    t1 = subStringMatchExact(target, key)
    t2 = subStringMatchOneSub(target, key)

    ans = ()
    for i in t2:
        if i not in t1:
            ans += (i, )
    return ans