python 集合常见运算交集并集差集

交集

set1 = {1,2,3,4,5,6,7,8,9}
set2 = {7,8,9,10,100,20,30}
set_val = set1.intersection(set2) #返回相同部分
print(set_val)
print(set1)
print(set2)

终端返回

{8, 9, 7}
{1, 2, 3, 4, 5, 6, 7, 8, 9}
{100, 20, 7, 8, 9, 10, 30}

set1 = {1,2,3,4,5,6,7,8,9}
set2 = {7,8,9,10,100,20,30}
set_val = set1.intersection_update(set2)#set1变成相同部分
print(set_val)
print(set1)
print(set2)

终端返回
None
{8, 9, 7}
{100, 20, 7, 8, 9, 10, 30}

并集

set_val = set1.union(set2) #两个集合合并到一起且去重
print(set_val)
print(set1)
print(set2)

终端返回

{1, 2, 3, 4, 5, 6, 7, 8, 9, 100, 10, 20, 30}
{1, 2, 3, 4, 5, 6, 7, 8, 9}
{100, 20, 7, 8, 9, 10, 30}

差集

set_val = set1.difference(set2)#返回set1不同到部分
print(set_val)
print(set1)
print(set2)

终端返回

{1, 2, 3, 4, 5, 6}
{1, 2, 3, 4, 5, 6, 7, 8, 9}
{100, 20, 7, 8, 9, 10, 30}