dict1 = {"k1":"v1","k2":"v2","k3":"v3"}

#for item in dict1:
    #print(item)

    #print(dict1.get(item))

    #print(item,dict1.get(item))

#dict1.setdefault("k4","v4")
#print(dict1)

#del dict1["k1"]

#dict1.pop("k5",None)
#print("删除不存在的k5,不报错，返回值: ",dict1.pop("k5",None))

#print(dict1.get("k2"))

#print("获取字典中k6对应的值,如果不存在，,返回值",dict1.get("k6"))
"""
t=(10,[20,30],9)
print(t)
print(type(t))
print(t[0],type(t[0]),id(t[0]))
for k in t:
    print(k)
"""
s={2,3,4,5,6}
#print(s)
s3=set(range(4))
#print(s3)
#print(set([2,3]))
#print(10 in s)
#s.add(40)
#s.update([36,5,4,2])
#s.pop()
#print(s)
#print(s!=s3)
#print(s.issubset(s3))
#print(s.issuperset(s3))
#print(s.isdisjoint(s3))
#print(s.intersection(s3))#交集
#print(s.union(s3))#并集
#print(s.difference(s3))#
#print(s.symmetric_difference(s3))#对称差集
#lst={i*i for i in range(6)}
#print(lst)