您可能要使用具有maxlen构造函数参数的collections.deque对象：
>>>l = collections.deque(maxlen=5)>>>l.append('apple')>>>l.append('orange')>>>l.append('grape')>>>l.append('banana')>>>l.append('mango')>>>print(l)deque(['apple','orange','grape','banana','mango'], maxlen=5)>>>l.append('kiwi')>>>print(l)deque(['orange','grape','banana','mango','kiwi'], maxlen=5) #only 5 items in list
