Python基础推导式

推导式 主要是针对可变数对象类型 list set dictionary
重点内容
1：列表推导式
[#逻辑体 for var in list]
例如 a = [1,3,4,5,5]
b = [var +1 for var in a]
结果是 [2,4,5,6,6]
2: 字段推导式
{key:value for key in dict}
例如 a = {1:”1”,2:”2”}
{key:int(a[key]+1) for key in a}
结果就是{1: 2, 2: 3}
3:集合推导式
[#逻辑体 for var in set]
例如 a = {1,2,3}
{var + 2 for var in a}
结果就是 {3,4,5}