栈 数组实现（python语言）

class StackArray:
    def __init__(self):  # 建空栈
        self.array = []

    def is_empty(self):  # 栈的判空
        if len(self.array) == 0:  # 如果为零
            return 0
        else:
            return 1

    def push(self, value):  # 入栈
        i = len(self.array)
        if i == 0:  # 空栈
            print('空栈\n')
            return error
        else:
            self.array[i+1] = value
            return self.array

    def pop(self):  # 出栈
        i = len(self.array)
        if i == 0:
            print('空栈\n')
            return error
        else:
            value = self.array[i]
            self.array[i] = None
        return value

    def top(self):  # 查看最后入栈的元素
        i = len(self.array)
        if i == 0:
            print('空栈\n')
            return error
        else:
            value = self.array[i]
        return value

    def show(self):  # 查看栈的所有元素
        if len(self.array) == 0:
            print('空栈')
            return error
        else:
            i = 0
        while self.array[i] is not None:
            print(self.array[i],end='\n')
            i += 1
        return