栈的实现

class Stack:
    def __init__(self):
        self.lis = []

    def pop(self):
        if not self.is_empty():
            return self.lis.pop()
        else:
            raise IndexError("The stack is empty!")

    def push(self, element):
        self.lis.append(element)

    def get_top(self):
        if len(self.lis) > 0:
            return self.lis[len(self.lis)-1]
        else:
            return None

    def get_len(self):
        return len(self.lis)

    def is_empty(self):
        return len(self.lis) == 0


def brace_match(s):
    stack = Stack()
    match = {')': '(', ']': '[', '}': '{'}
    for ch in s:
        if ch in match.values():
            stack.push(ch)
        elif ch not in match.keys():
            return False
        else:
            if stack.get_top() == match[ch]:
                stack.pop()
            else:
                return False
    else:
        if stack.get_len() == 0:
            return True
        else:
            return False


if __name__ == '__main__':
    stack = Stack()
    test_str = '{[(({('
    print(brace_match(test_str))