Matching parens

matching.py

def match(s, pairs):
    stack = []
    closers = set(pairs.values())

    for c in s:
        if c in pairs:
            stack.append(pairs[c])
        elif c in closers:
            # we can end early if either is true
            if not stack or c != stack.pop():
                return False
    return not stack

# from the example
m = {
    '{':'}',
    '[':']',
    '(': ')'
}

# tests
print match(')()', m) == False
print match('({[]})', m) == True
print match('aaaaaa({[]}aaaaaaaaaaaaaaa)', m) == True
print match('aaaaaa({[]}aaaaaaaaaaaaaaa', m) == False