Python—集合

一.集合的操作

1.集合的创建

set1 =set({1,2,'barry'})
set2 = {1,2,'barry'}
print(set1,set2)　

2.集合的增

set1 = {'alex','wusir','ritian','egon','barry'}
set1.add('17')
print(set1)

#update：迭代着增加
set1.update('A')
print(set1)
set1.update('老师')
print(set1)
set1.update([1,2,3])
print(set1)

3.集合的删

set1 = {'alex','wusir','ritian','egon','barry'}

set1.remove('alex') #删除一个元素
print(set1)

set1.pop() #随机删除一个元素
print(set1)

set1.clear() #清空集合
print(set1)

del set1  #删除集合
print(set1)

　　

二.集合的其他操作

1.交集

set1 = {1,2,3,4,5}
set2 = {4,5,7,8,9}
print(set1 & set2)
print(set1.intersection(set2))

2.并集

print(set1 | set2)
print(set1.union(set2))

3.反交集

print(set1 ^ set2)
print(set1.symmetric_difference(set2))

4.子集与超集

print(set1 < set2)
print(set1.issubset(set2))

print(set2 > set1)
print(set2.issuperset(set1))

s = frozenset('barry')
print(s,type(s))