python语法基础：列表

list1 = [1,2,3,4,4,4]
set1 = set(list1)
print(set1)
set2 = {1,2,4}#不写K-V类型的，默认就是set集合
set3 = set([1,2,'1'])#必须要加中括号，与上面不一样，两种方法都是创建set集合，后者强转
print(type(set2))
print(set3)

list1 = {1,2,3,4,5}
list2 = {3,4,5,6,7}
print(list1.union(list2))#并集
print(list1.intersection(list2))#交集
print(list1.difference(list2))#等同于list1-list2
print(list2.difference(list1))#等同于list2-list1

list1 = {1,2,3}
list2 = {1,2}
print(list2.issubset(list1))#判断list2是否是list1的子集，等同于list2 < list1
print()

list1 = {1,2,3}
list1.add(4)
print(list1)
list1.update([5,6])#必须是集合
print(list1)
list1.remove(1)
print(list1)

控制台：

{1, 2, 3, 4}
<class 'set'>
{'1', 1, 2}
{1, 2, 3, 4, 5, 6, 7}
{3, 4, 5}
{1, 2}
{6, 7}
True
{1, 2, 3, 4}
{1, 2, 3, 4, 5, 6}
{2, 3, 4, 5, 6}