python中集合

去重 无序 没有索引

#remove 删除元素

>>> s1 = {1,2,3,4,5}
>>> s1.remove(2)
>>> print(s1)
{1, 3, 4, 5}

#pop 剪切

>>> s1 = {1,2,3,4,5}
>>> res = s1.pop()
>>> print(res)
1

#add 添加

>>> s1 = {1,2,3,4,5}
>>> s1.add('')
>>> print(s1)
{1, 2, 3, 4, 5, ''}

#update 添加新的元素

>>> s1 = {1,2,3,4,5}
>>> s1.update('','','','')
>>> print(s1)
{1, 2, 3, 4, 5, '', '', '', ''}

#判断一个集合是否是另一个集合的子集

>>> s1 = {1,2,3,4,5}
>>> s2 = {1,2,3}
>>> res = s2.issubset(s1)
>>> print(res)
True

#union 并集

>>> s1 = {1,2,3,4,5}
>>> s2 = {1,2,3,7}
>>> print(s2.union(s1))
{1, 2, 3, 4, 5, 7}

#intersection 交集

>>> s1 = {1,2,3,4,5}
>>> s2 = {1,2,3,7}
>>> print(s1.intersection(s2))
{1, 2, 3}