class Stack(object): def __init__(self): self.stack=[] def pop(self): return self.stack.pop() def push(self,item): return self.stack.append(item) def isempity(self): if len(self.stack)==0: return True else: return False def size(self): return len(self.stack) def get_stack(self): return self.stack if __name__ == '__main__': pass