python学习（索引），,一.索引1.索引值从

python学习（索引），,一.索引1.索引值从

一.索引

1.索引值从左到右-->从0开始，索引值从右到左-->从-1开始

>>> name = "xinfangshuo">>>>>> name[0]‘x‘>>> name[5]‘n‘>>> name[-1]‘o‘>>> name[-2]‘u‘

2.注意：整型int和字典dict和集合set不支持索引取值

>>> age = 123>>>>>> age[1]Traceback (most recent call last):  File "<stdin>", line 1, in <module>TypeError: ‘int‘ object has no attribute ‘__getitem__‘>>> age = "123">>> age[1]‘2‘>>> name = {"name1":"zhangsan","name2":"lisi","name3":"wangwu"}>>>>>> name[1]Traceback (most recent call last):  File "<stdin>", line 1, in <module>KeyError: 1>>>>>> set = {"zhangsan","lisi","wangwu"}>>>>>> set[1]Traceback (most recent call last):  File "<stdin>", line 1, in <module>TypeError: ‘set‘ object does not support indexing

3.多维数组/列表，索引取值

"""多维数组，索引取值""">>> name = ("zhangsan","lisi","wangwu","zhaoliu","wangba",("zhengying","lizhipeng","lvlinlin"))>>>>>> name[5][1]‘lizhipeng‘>>>>>> list = [1,2,3,4,[5,6,7,[8,9,0]]]>>>>>> list[4][3][1]9>>> list[-1][-1][-2]9

python学习（索引）