列表 list.pop(obj=list[-1])
pop()用于删除并返回列表中的一个元素(默认为最后一个元素)
字典dict.pop(key[,default])
pop()用于删除字典中给定的key及对应的value,返回被删除key对应的value,key值必须给出。给定的key值不在字典中时,返回default值。
实例:
>>> list1 = [1,2,4,"hello","xy","你好"] >>> a = list1.pop()#默认弹出最后一个元素 >>> print(a,list1) 你好 [1,2,4,"hello","xy"] >>> list2 = [1,2,4,"hello","xy","你好"] >>> b = list2.pop(3)#弹出列表中第四个元素 >>> print(b,list2) hello [1,2,4,"xy","你好“]
>>> dict1 = {"papa":"xy","sis":"nikki","dude":"cwy"}
>>> c = dict.pop()#不给定key值报错
Traceback (most recent call last):
File "", line 1, in
c = dict.pop()
TypeError: unbound method dict.pop() needs an argument
>>> dict1 = {"papa":"xy","sis":"nikki","dude":"cwy"}
>>> c = dict1.pop("papa")
>>> print(c,dict1)
xy {'sis': 'nikki', 'dude': 'cwy'}
>>> dict2 = {"papa":"xy","sis":"nikki","dude":"cwy"}
>>> d = dict2.pop("www")#给定键不在字典内时,未设置default值报错
Traceback (most recent call last):
File "", line 1, in
d = dict2.pop("www")
KeyError: 'www'
>>> dict2 = {"papa":"xy","sis":"nikki","dude":"cwy"}
>>> d = dict2.pop("www","不在字典内")
>>> print(d,dict2)
不在字典内 {'papa': 'xy', 'sis': 'nikki', 'dude': 'cwy'}