求兩個列表的交集、並集、差集

a=[1,2,3,4]
b=[3,4,5,6]

jiaoji=[i for i in a if i in b]
print("a和b的交集：%s" % jiaoji)

bingji=list(set(a).union(set(b)))
print("a和b的並集： %s" % bingji)

chaji=set(a).difference(set(b))
print("a和b的差集：%s" %chaji)
chaji2=set(b).difference(set(a))
print("b和a的差集:%s" % chaji2)