python基础之集合set

集合：set 可变数据类型，包含的数据必须是不可变数据类型、无序、不重复,表示：{}

不可变数据类型：tuple、bool、int、str    --可哈希类型
可变数据类型：list、dict、set --不可哈希类型

增：set.add(obj) set.update(obj)
删：set.pop()  set.remove(obj) set.clear()  del set
查：for i in set:
集合间交换数据：交集：set1&set2 set1.intersection(set2)  并集：set1|set2  set1.union(set2)
                反交集： set1^set2 set1.symmeterc_difference(set2)  差集：set1-set2  set1.difference(set2)
                子集：set1<set2  set1.issubset(set2)   超集：set1>set2  set1.issuperset(set2)
统计：len(set)
定义：
ey:

set1 = set({1,2,3,4})
print(set1)

set1 = {1,2,3,4}
print(set1)

result:{1, 2, 3, 4}
ey:

set1 = set({1,2,3,4,[12,2]})
print(set1)

result:TypeError: unhashable type: 'list'
1，增：add
ey:

set1 = set({1,2,3,4})
set1.add('1')
print(set1)

result:{1, 2, 3, 4, '1'}
update():打散后追加
ey:

set1 = set({1,2,3,4})
set1.update('ssswe')
print(set1)

result:{1, 2, 3, 4, 's', 'w', 'e'}
2，删
pop()从左开始删
ey:

set1 = set({1,2,3,4})
set1.pop()
print(set1)

result:{2, 3, 4}
remove(obj)按元素删
ey:

set1 = set({1,2,3,4})
set1.remove(3)
print(set1)

result:{1, 2, 4}
clear()清除
ey:

set1 = set({1,2,3,4})
set1.clear()
print(set1)

result:set()
del 删除
ey:

set1 = set({1,2,3,4})
del set1
print(set1)

result:NameError: name 'set1' is not defined
4，查
ey:

set1 = set({1,2,3,4})
for i in set1:
    print(i)

result:1,2,3,4
5,统计

set1 = set({1,2,3,4})
print(len(set1))

result:4
6,交集

set1 = set({1,2,3,4})
set2 = {2,3,8,9,0}
print(set1&set2)

result:{2, 3}

set1 = set({1,2,3})
set2 = {1,2,3,5,6}
print(set2.intersection(set1))

result:{1, 2, 3}
7,并集

set1 = set({1,2,3,4})
set2 = {2,3,8,9,0}
print(set1|set2)

result:{0, 1, 2, 3, 4, 8, 9}

set1 = set({1,2,3,4})
set2 = {2,3,8,9,0}
print(set1.union(set2))

result:{0, 1, 2, 3, 4, 8, 9}
8,反交集

set1 = set({1,2,3,4})
set2 = {2,3,8,9,0}
print(set1^set2)

result:{0, 1, 4, 8, 9}

set1 = set({1,2,3,4})
set2 = {2,3,8,9,0}
print(set1.symmetric_difference(set2))

result:{0, 1, 4, 8, 9}
9，差集：--存在于set1，不存在于set2

set1 = set({1,2,3,4})
set2 = {2,3,8,9,0}
print(set1-set2)

result:{1, 4}

set1 = set({1,2,3,4})
set2 = {2,3,8,9,0}
print(set1.difference(set2))

result:{1, 4}
10,子集：set1是set2的子集

set1 = set({1,2,3})
set2 = {1,2,3,5,6}
print(set1<set2)

result:True

set1 = set({1,2,3})
set2 = {1,2,3,5,6}
print(set1.issubset(set2))

result:True
11,超集:set2是set1的超集

set1 = set({1,2,3})
set2 = {1,2,3,5,6}
print(set2>set1)

result:True

set1 = set({1,2,3})
set2 = {1,2,3,5,6}
print(set2.issuperset(set1))

result:True