python实现栈的基本操作

题目：自定义类实现栈，要求：初始化栈，清空栈，判断栈是否为空栈，获取栈的长度，获取栈顶元素，入栈，出栈，栈的遍历。

以链栈为例！！！！

具体代码：

# 链栈的实现
class Node(object):
    def __init__(self, data=None, next_=None):
        self.data = data
        self.next_ = next_


class LinkStack(object):
    # 初始化栈
    def __init__(self):
        self.top = None

    # 清空栈
    def clearStack(self):
        self.top = None
        print("栈已经清空")

    # 判断栈是否为空
    def isEmpty(self):
        return self.top is None

    # 求栈的大小
    def length(self):
        i = 0
        p = self.top
        while p is not None:
            p = p.next_
            i += 1
        return i

    # 求栈顶元素
    def peek(self):
        p = self.top
        if p is not None:
            return p.data
        else:
            print("空栈")

    # 入栈
    def push(self, data):
        s = Node(data, self.top)
        self.top = s

    # 出栈
    def pop(self):
        if self.isEmpty():
            return None
        p = self.top