python中对两个 list 求交集，并集和差集

python中对两个 list 求交集，并集和差集：

1、首先是较为浅白的做法：

>>> a=[1,2,3,4,5,6,7,8,9,10]
>>> b=[1,2,3,4,5]
>>> intersection=[v for v in a if v in b]
>>> intersection
[1, 2, 3, 4, 5]
>>> union=b.extend([v for v in a])
>>> union
>>> b
[1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>>> difference=[v for v in a if v not in b]
>>> difference
[]

>>> a=[1,2,3,4,5,6,7,8,9,10]
>>> b=[1,2,3,4,5]
>>> difference=[v for v in a if v not in b]
>>> difference
[6, 7, 8, 9, 10]

2、效率较高的、并且可以去除重复数据的做法：

>>> a=[1,2,3,4,5,6,7,8,9,10]
>>> b=[1,2,3,4,5]
>>> intersection=list(set(a).intersection(set(b)))
>>> intersection
[1, 2, 3, 4, 5]
>>> union=list(set(a).union(set(b)))
>>> union
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>>> difference = list(set(a).difference(set(b)))
>>> difference
[8, 9, 10, 6, 7]

【Reference】

1、https://www.cnblogs.com/chen-kh/p/7137565.html