python列表的交、並、差集

#!/usr/bin/env python3

l1 = ['1','2','3','4']
l2 = ['3','4','5','6']

# 交集
result1 = [i for i in l1 if i in l2]
result2 = list(set(l1).intersection(set(l2)))
print(result1)
print(result2)

# 並集
result3 = list(set(l1).union(set(l2)))
print(result3)

# 差集
# 元素在 l1 不在 l2
result4 = list(set(l1).difference(set(l2)))
print(result4)