python集合

#集合(确定的无序的一组数据)

#集合函数
'''
#add() 向集合中添加元素
girls = {'mf','sl','yj'}
girls.add('xf')
print(girls)

#pop() 随机删除集合中的一个元素
boys = {'bd','zw','jl','zy'}
result = boys.pop()
print(boys)
print(result)

#remove() 删除集合中指定的元素 删除不存在的元素会报错
boys = {'bd','zw','jl','zy'}
boys.remove('zy')
print(boys)

#discard() 删除集合中指定的元素 删除不存在的元素啥都不做
boys = {'bd','zw','jl','zy'}
boys.discard('zy1')
print(boys)

#clear() 清空集合
boys = {'bd','zw','jl','zy'}
boys.clear()
print(boys)

#copy() 复制集合
boys = {'bd','zw','jl','zy'}
newboys = boys.copy()
print(newboys)
'''

#difference() 计算2个集合的差集
dreamers = {'ljl','wc','xy','zb','lsy'}
girls = {'mmf','lsy','syj'}
result = dreamers.difference(girls)# result = a - b，即result = {'ljl','wc','xy','zb'}
print(result)

#difference_update() 计算2个集合的差集(差集更新操作)
dreamers = {'ljl','wc','xy','zb','lsy'}
girls = {'mmf','lsy','syj'}
dreamers.difference_update(girls)#a = a - b 
print(dreamers)

#union() 并集操作
dreamers = {'ljl','wc','xy','zb','lsy'}
girls = {'mmf','lsy','syj'}
result = dreamers.union(girls)
print(result)

#update() 并集更新操作
dreamers = {'ljl','wc','xy','zb','lsy'}
girls = {'mmf','lsy','syj'}
dreamers.update(girls)
print(dreamers)

 

#symmetric_difference() 交叉并集

dreamers = {'ljl','wc','xy','zb','lsy'}

girls = {'mmf','lsy','syj'}

result = dreamers_difference(girls)

print(result)

 

#intersection() 计算2个集合的交集
dreamers = {'ljl','wc','xy','zb','lsy'}
girls = {'mmf','lsy','syj'}
result = dreamers.intersection(girls)
print(result)

#intersection_update 交集更新操作
dreamers = {'ljl','wc','xy','zb','lsy'}
girls = {'mmf','lsy','syj'}
dreamers.intersection_update(girls)
print(dreamers)

#父集和子集
boys = {'zzy','yqw','dw','wzc','lyb','wym','chy'}
zoudu = {'wzc','lyb','wym'}
girls = {'lsy','mmf','syj'}

#issuperset() 检测当前集合是否是另一个集合的父集
result = boys.issuperset(zoudu)
print(result)

#issubset() 检测当前集合是否是另一个集合的子集
result = zoudu.issubset(boys)
print(result)

#isdisjoint() 检测2个集合是否不存在交集 存在交集 False
result = boys.isdisjoint(girls)
print(result)

#symmetric_difference() 对称差集
dreamers = {'ljl','wc','xy','zb','lsy'}
girls = {'mmf','lsy','syj'}
result = dreamers.symmetric_difference(girls)
print(result)

#symmetric_difference_update() 对称更新差集
dreamers = {'ljl','wc','xy','zb','lsy'}
girls = {'mmf','lsy','syj'}
dreamers.symmetric_difference_update(girls)
print(dreamers)

#冰冻集合
#冰冻集合是一种特殊的集合类型,也是集合(集合是列表的话,冰冻集合就是元组)
#创建冰冻集合
#一般不会创建空的冰冻集合
var = frozenset()
print(var,type(var))

#带有数据的冰冻集合
var = frozenset(('qs','szx','bjh','acs'))
print(var,type(var))

 

#函数
#冰冻集合可以使用集合的函数(不修改集合本身的函数都可以使用)
var = frozenset(('qs','szx','bjh','acs'))

#copy()
result = var.copy()
print(result)