list1=[1,2,3,4]
s=set(list1)
print(s)
#逐个遍历
for i in s:
  print(i)

输出:
set([1, 2, 3, 4])
1
2
3
4

list1=[1,2,3,4]
s=set(list1)
print(s)
s.add(4)
s.add(5)
print(s)

输出：
set([1, 2, 3, 4])
set([1, 2, 3, 4, 5])

list1=['a','b','zhang','kang']
s=set(list1)
print(s)
s.remove('zhang')
print(s)

输出：
set(['a', 'kang', 'b', 'zhang'])
set(['a', 'kang', 'b'])

list1=['a','b','zhang','kang']
list2=['a','b','c','d']
s1=set(list1)
s2=set(list2)
#交集，使用&操作符
s3=s1&s2
#并集，使用|操作符
s4=s1|s2
print(s3)
print(s4)

输出:
set(['a', 'b'])
set(['a', 'c', 'b', 'd', 'zhang', 'kang'])