from collections.abc import Mapping,MutableMapping
# dict 属于mapping类型a = {}
print(isinstance(a,MutableMapping))

a = {"bobby1":{"company":"imooc"},"bobby2:":{"company":"imooc"}}# clear
# a.clear()#copy,返回浅拷贝
# new_dict = a.copy()
# new_dict["bobby1"]["company"] = "imooc3"# 深拷贝
# import copy
# new_dict = copy.deepcopy(a)
# new_dict["bobby1"]["company"] = "imooc3"# fromkeys
new_list = ["bobby1","bobby2"]
new_dict = dict.fromkeys(new_list,{"company":"imooc"})# get
# value = new_dict.get("bobby",{})
# print(value)#items
# for key,value in new_dict.items():
#     print(key,value)# setdefault
# 他对去调用D.get(k,d)同时D[k] 设置
default_value = new_dict.setdefault("bobby","imooc")
print(new_dict)# update:
new_dict.update(bobby="imooc")
new_dict.update([("bobby","imooc")])
new_dict.update((("bobby","imooc"),))

# 不建议继承list和dict
class Mydict(dict):def __setitem__(self,key,value):super().__setitem__(key,value*2)my_dict = Mydict(one=1)
my_dict["one"] = 1
print(my_dict)

# 建议用UserDict
from collections import UserDictclass Mydict(UserDict):def __setitem__(self,key,value):super().__setitem__(key,value*2)my_dict = Mydict(one=1)
print(my_dict)

from collections import defaultdictclass Mydict(UserDict):def __setitem__(self,key,value):super().__setitem__(key,value*2)my_dict = Mydict(one=1)
print(my_dict)my_dict = defaultdict(dict)
my_value = my_dict["bobby"]# __missing__方法，如果找不到某个key，那么实现一个keyvalue

# set   集合  frozenset   不可变集合   无序  不重复
s = set('abcde')
s = set(['a','b','c'])
print(s)# 初始化方法
s = {'a','b'}
print(type(s))s2 = frozenset('abcde') # 不可变的类型，可以作为dict的key
print(s2)

for "c" in set:print ("i am in set")