python 括号检测(基于pythonds)

from pythonds.basic.stack import Stack
def parChecker(symbolString):
    s = Stack()
    balanced = True
    index = 0
    while index < len(symbolString) and balanced:
        symbol = symbolString[index]
        if symbol  in  "([{":
            s.push(symbol)
        else:
            if s.isEmpty():
                balanced = False
            else:
                top = s.pop()
                if not matches(top,symbol):
                    balanced = False
        index = index 1
    if balanced and s.isEmpty():
        return True
    else:
        return False
def matches(open,close):
    opens  = "([{"
    closer = ")]}"
    return opens.index(open) == closer.index(close)
print(parChecker('{{([][])}()}'))
print(parChecker('[{()]'))