python中pop类型是什么_python中pop()函数的语法与实例

语法:

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)

obj:要删除并返回的列表元素

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。

key:需要删除的key值(不给出会报错)

default:若没有字典中key值,返回default值(给定的key值不在字典中时必须设置,否则会报错)

实例:

列表

>>> 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“]

字典

>>> 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"}

总结

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原文链接:https://blog.csdn.net/m0_52825771/article/details/110360237

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