python集合的创建、添加及删除操作示例

> num={1,2,3,4}

> a=set(range(1,4))
> a
{1, 2, 3}

> b=set([1,2,3,4,5,6])
> b
{1, 2, 3, 4, 5, 6}

> num={1,2,3,4}
> num.add(0)
> num
{0, 1, 2, 3, 4, 8}

> num={1,2,3,4}
> del num
> num
Traceback (most recent call last):
 File "<pyshell#84>", line 1, in <module>
  num
NameError: name 'num' is not defined

> a = {1, 4, 2, 3}
> a.clear()
> 
> a
set()

> b=set([1,2,3,4,5,6])
> b
{1, 2, 3, 4, 5, 6}
> b.remove(1)
> b
{2, 3, 4, 5, 6}
> b.remove(2)
> b
{3, 4, 5, 6}

>a = {1, 4, 2, 3}
>a.pop()
1
>a.pop()
2
>a
{3,4}