使用栈进行括号匹配

from pythonds.basic.stack import Stack
def parchecker(SymbolString):
    s=Stack()
    balance=True
    index=0
    for i in range(len(SymbolString)):
        if SymbolString[i]=='(':
            s.push(SymbolString[i])
        elif s.isEmpty():
            balance=False      #检验只有‘)’的情况
        else:
            s.pop()
    if balance and s.isEmpty():
        result=True
    else:
        result=False
    return result
print(parchecker('((()))'))