set = {1,2,3,('12','二')}
集合跟字典差不多,但没有键值对,其中不能放可变变量
特性:去重,无序
一。增:2种方式
1.add 添加为一个元素
set.add('名字'); //{'名字',1,2,3,('12','二')}
2.update 迭代添加
set..update('abcd') //{'名字','a','b','c','d',1,2,3,('12','二')}
二。删除
1.随机删除,pop() 并返回删除的值
print(set.pop())
2按元素删除
set.remove('a')
3.清空、
set.clear()
4.删除整个集合
del set
print(set) //报错
三。查看
for i in set:
print(i)
四。求交集
set1 = {1,2,3,4,5}
set2 = {4,5,6,7,8}
1.set3 = set1 & set2
print(set3) //{4,5}
2.
print(set1.intersection(set2)) // {4,5}
五,并集
set1 = {1,2,3,4,5}
set2 = {4,5,6,7,8}
1.set3 = set1 | set2
print(set3) //{1,2,3,4,5,6,7,8}
2
print(set2.union(set1)) //{1,2,3,4,5,6,7,8}
六。差集
set1 = {1,2,3,4,5}
set2 = {4,5,6,7,8}
1.set3 = set1 - set2
print(set3) //{1,2,3} set1独有的
2
print(set1.difference(set2))
七。子集与超集
set1 = {1,2,3}
set2 = {1,2,3,4,5,6{
1。子集
print(ste1 < set2) //true
print(set1.issubset(set2) //true 这两个相同,都是说明set1是set2的子集
2.超集
print(set2 > set1)
print(set2.issuperset(set1)) //true 说明set2是set1的超集
八。去重
li = [1,2,3,3,4,4,5,6]
set1 = set(li)
print(set) //{1,2,3,4,5,6}
li = list(set1)
print(li) //[1,2,3,4,5,6]
九。不可变集合
特性:无序,只读
s = frozenset(abcdd')
print(s,type(s)) //{'a','b','c','d'}