ps3d.py

def subStringMatchExactlyOneSub(target,key):

    exactMatch = list(subStringMatchExact(target,key))
    constrainedMatchOneSub = list(subStringMatchOneSub(key, target))

    # Now I have to compare each element of exactMatch list to each element of constrainedMatchOneSub list.
    # The goal is to drop own all elements of constrainedMatchOneSub list that are equal to elements of
    # exactMatch list

    # this is the idex of constrainedMatchOneSub list

    i = 0

    # the length of constrainedMatchOneSub list decreases as elements are removed

    for j in range(len(exactMatch)):
        while i < len(constrainedMatchOneSub):
            if exactMatch[j] == constrainedMatchOneSub[i]:
                constrainedMatchOneSub.pop(i)
            else:
                i += 1
        i = 0
    constrainedMatchOneSubTuple = tuple(constrainedMatchOneSub)
    return constrainedMatchOneSubTuple