基于list来实现一个栈：
代码语言：javascript复制class SimpleStack:
def __init__(self):
self.__stack: list = []
def __iter__(self):
return SimpleStackIterator(self)
def __len__(self):
return len(self.__stack)
def __getitem__(self, index):
if index >= len(self.__stack):
return None
return self.__stack[index]
def pop(self):
if len(self.__stack) <= 0:
return None
return self.__stack.pop()
def push(self, item):
return self.__stack.append(item)定义一个栈的迭代器，实现对栈进行迭代，但不弹出栈中的元素
代码语言：javascript复制class SimpleStackIterator:
def __init__(self, iterable: SimpleStack):
self.__iterable = iterable
self.__len = len(iterable)
self.__current = 0
def __iter__(self):
return self
def __next__(self):
while True:
if self.__current >= self.__len:
raise StopIteration
ele = self.__iterable[self.__current]
self.__current = 1
return ele具体使用：
代码语言：javascript复制stack_size = 5
stack = SimpleStack()
for i in range(stack_size):
stack.push(i)
for i in iter(stack):
print(i)
for i in range(stack_size):
ele = stack.pop()
print(ele)
