组的概念
一. 列表 list
[1,2,3]
二. 元组 tuple
(1,2,3)
(1,2,3)[0]
> 1
(1,2,3)[0:2]
> (1,2) # 第0位到第2位,左闭右开
(1,2,3)+(4,5,6)
> (1,2,3,4,5,6)
(1,2,3)*3
> (1,2,3,1,2,3,1,2,3)
三. 集合 set
无序,去重
type({1,2,3})
> class 'set'
{1,2,3,4,5,6} - {3,4}
> {1,2,5,6}
# 差集
{1,2,3,4,5,6} & {3,4}
> {3,4}
# 交集
{1,2,3,4,5,6} | {3,4,7}
> {1,2,3,4,5,6,7}
# 并集
四. 字典 dict
key-value