test.py 760 B

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  1. class Stack(object):
  2. """栈"""
  3. def __init__(self):
  4. self.items = []
  5. def is_empty(self):
  6. """判断是否为空"""
  7. return self.items == []
  8. def push(self, item):
  9. """加入元素"""
  10. self.items.append(item)
  11. def pop(self):
  12. """弹出元素"""
  13. return self.items.pop()
  14. def peek(self):
  15. """返回栈顶元素"""
  16. return self.items[len(self.items)-1]
  17. def size(self):
  18. """返回栈的大小"""
  19. return len(self.items)
  20. if __name__ == "__main__":
  21. stack = Stack()
  22. stack.push("hello")
  23. stack.push("world")
  24. stack.push("itcast")
  25. print(stack.size())
  26. print(stack.peek())
  27. print(stack.pop())
  28. print(stack.pop())
  29. print(stack.pop())