# 集合的定义
s = set()
print(type(s))
print(s)
print("*"*30)

# 此时，大括号内一定要有值，否则定义出的是一个dict
s = {}
print(type(s))
print(s)
print("*"*30)

s = {1,2,3,4,5}
print(type(s))
print(s)

# 如果只是用大括号定义，则定义的是一个dict类型
d = {}
print(type(d))
print(d)

# 成员检测
# in not in
s = {4,5,"i", "love", "python"}
print(s)

if "love" in s:
    print("爱呀")

if  "haha" not in s:
    print("挨个锤子")

# for 循环
s = {4,5,"i", "love", "python"}

for i in s:
    print(i, end=" ")
# 得到的结果就是随机的

# 带有元组的集合遍历
s = {(1,2,3), ("i", "love", "python"), (4,5,6)}

for k,m,n in s:
    print(k, "--", m, "--", n)
    
for k in s:
    print(k)

# 普通集合的内涵
# 以下的集合
s = {1,2,3,5,6,2,3,5,1,2,3,2,2,8,4,6,2}
print(s)


# 普通集合的内涵
ss = {i for i in s if i % 2==0}
print(ss)

# 带有条件的集合内涵
ss = {i for i in s if i % 2==0}
print(ss)

# 多重循环的集合内涵
s1 = {1,2,3,4}
s2 = {"i","love","python"}
s = {m*n for m in s2 for n in s1}
print(s)

# len, max, min:跟其他基本函数一致
s = {43,23,56,223,4,2,1222,4,323,1}
print(len(s))
print( max(s))
print(min(s))

# set:生成一个集合
l = [1,2,3,4,3,23,1,2,3,4]
s = set(l)
print(s)

# add：向集合内添加元素
s = {1}
s.add(2)
print(s)

# clear 
s = {1,5,6,8}
print(s)
print(id(s))
s.clear()
print(s)
print(id(s))
# 结果表明ｃｌｅａｒ函数是原地清空数据

# copy:拷贝
# remove:移除制定的值，直接改变原有值，如果要删除的值不存在，报错
# discard:移除集合中指定的值，跟ｒｅｍｖｏｅ一样，但是如果要删除的话，不报错
s = {23,3,4,5,1,2,3}
s.remove(4)
print(s)
s.discard(1)
print(s)

print("*" * 20)
s.discard(1100)
print(s)

s.remove(1100)
print(s)

# 为啥remove不存在的值会报keyerror 思考？

# pop 随机移除一个元素
s = {1,5,2,3,5,6}
d = s.pop()
print(s)
print(d)

# 集合函数
# intersection()；交际
# difference()：差集
# union：并集
# issubset: 检查一个集合是否为另一个子集
# issuperset: 检查一个集合是否为另一个超集
s1 = {1,2,3,4,5,6}
s2 = {5,6,7,8,9}

s_1 = s1.intersection(s2)
print(s_1)

s_2 = s1.difference(s2)
print(s_2)

s_3 = s1.issubset(s2)
print(s_3)

# 集合数学操作
s1 = {1,2,3,4,5,6}
s2 = {5,6,7,8,9}

s_1 = s1 - s2
print(s_1)

s_2 = s1 + s2
print(s_2)
# 此处不支持数学操作中的+操作