Python数据结构--栈

class Stack(object):    def __init__(self):        self.stack = []    # 判断栈是否为空    def isEmpty(self):        return self.stack == []    # push压栈操作    def push(self,item):        self.stack.append(item)    # pop出栈操作    def pop(self):        if self.isEmpty():            return None # 空则返回none        return self.stack.pop()    # 返回栈顶元素    def peek(self):        return self.stack[-1]    # 栈中元素的个数    def size(self):        return len(self.stack)if __name__ == '__main__':    s = Stack()    for i in range(1,10):        s.push(i)    print('--',s.stack)    s.pop()    print('--',s.stack)