python3 set(集合)

add(增加元素)

name = set(['Tom','Lucy','Ben'])
name.add('Juny')
print(name) #输出:{'Lucy', 'Juny', 'Ben', 'Tom'}

clear(清空所有元素)

name = set(['Tom','Lucy','Ben'])
name.clear()
print(name) #输出:set()

copy(拷贝set集合)

name = set(['Tom','Lucy','Ben'])
new_name = name.copy()
print(new_name) #输出:{'Tom', 'Lucy', 'Ben'}

difference(返回两个或多个集合中不同的元素,并生成新的集合)

A = set([2,3,4,5])
B = set([3,4])
C = set([2])
n = A.difference(B,C)
print(n) #输出:{5}
#返回A集合里面,在B和C集合中没有的元素,并生成新的集合

difference_update(删除A集合里面,在B集合中存在的元素。)

A = set([2,3,4,5])
B = set([4,5])
A.difference_update(B)
print(A) #输出:{2, 3}

discard(移除元素,如果元素不存在不报错)

n = set([2,3,4])
n.discard(3)
print(n) #输出:{2, 4}

intersection(取交集,并生成新的集合)

n1 = set([2,3,4,5])
n2 = set([4,5,6,7])
n = n1.intersection(n2)
print(n) #输出:{4, 5}

intersection_update(取交集,修改原来的集合)

n1 = set([2,3,4,5])
n2 = set([4,5,6,7])
n1.intersection_update(n2)
print(n1) #输出:{4, 5}

isdisjoint(判断交集,是返回False,否返回True)

n1 = set([2,3,4,5])
n2 = set([4,5,6,7])
print(n1.isdisjoint(n2)) #输出:False

issubset(判断子集)

A = set([2,3])
B = set([2,3,4,5])
print(A.issubset(B)) #输出:True
#A是B的子集

issuperset(判断父集)

A = set([2,3])
B = set([2,3,4,5])
print(B.issuperset(A)) # 输出:True
#B是A的父集

pop(随机移除一个元素)

n = set([2,3,4,5])
n1 = n.pop()
print(n,n1) # 输出:{3, 4, 5} 2

remove(移除指定元素,元素不存在会报错)

n = set([2,3,4,5])
n.remove(2)
print(n) # 输出:{3, 4, 5}

symmetric_difference(取交集,并生成新的集合)

A = set([2,3,4,5])
B = set([4,5,6,7])
print(A.symmetric_difference(B)) # 输出:{2, 3, 6, 7}

symmetric_difference_update(取交集,改变原来的集合)

A = set([2,3,4,5])
B = set([4,5,6,7])
A.symmetric_difference_update(B)
print(A) # 输出:{2, 3, 6, 7}

union(取并集,并生成新的集合)

A = set([2,3,4,5])
B = set([4,5,6,7])
print(A.union(B)) # 输出:{2, 3, 4, 5, 6, 7}

update(取并集,改变原来的集合)

A = set([2,3,4,5])
B = set([4,5,6,7])
A.update(B)
print(A) # 输出:{2, 3, 4, 5, 6, 7}
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