import pickle
class Cat:def __init__(self, name, age):self.name = nameself.age = agedef catchMouse(self):print(self.name, "抓老鼠")c = Cat("jerry", 18)
bs = pickle.dumps(c) # 序列化一个对象.
print(bs) # ⼀堆⼆进制. 看不懂
cc = pickle.loads(bs) # 把二进制反序列化成我们的对象
cc.catchMouse() # 猫依然是猫. 还可以抓老鼠

import shelve
shelf = shelve.open("sylar")
# shelf["jay"] = "周杰伦"
print(shelf['jay'])
shelf.close()
s = shelve.open("sylar")
# s["jay"] = {"name":"周杰伦", "age":18, "hobby":"哄小孩"}
print(s['jay'])
s.close()

s = shelve.open("sylar")
s['jay']['name'] = "胡辣汤" # 尝试改变字典中的数据
s.close()
s = shelve.open("sylar")
print(s['jay']) # 并没有改变
s.close()

解决方案:
s = shelve.open("sylar", writeback=True)
s['jay']['name'] = "胡辣汤" # 尝试改变字典中的数据
s.close()
s = shelve.open("sylar")
print(s['jay']) # 改变了.
s.close()

s = shelve.open("sylar", writeback=True)
del s['jay']
s.close()
s = shelve.open("sylar")
print(s['jay']) # 报错了, 没有了
s.close()

s = shelve.open("sylar", writeback=True)
s['jay'] = "周杰伦"
s['wlj'] = "王力宏"
s.close()
s = shelve.open("sylar")
for k in s: # 像字典那样遍历print(k)

print(s.keys()) # 拿到所有key的集合
for k in s.keys():
print(k)

for k, v in s.items(): # 像字典一样操作
print(k, v)
s.close()

# ----- loads  转换字符串到json ----------------
s1 = '{"1":"毒液","2":"雷神","3":"海王","4":false,"5":null}'
d = json.loads(s1)
print(d)

# --------------字符串 转 字典  进文件----------------dic1 = {"1":"毒液","2":"雷神","3":"海王","4":False,"5":None,"6":{"想看":"没钱","能看":"没时间"}}
f = open("du.json",mode="w",encoding="utf-8")
json.dump(dic1,f,ensure_ascii=False,indent=4)
f = open("du.json",mode="r",encoding="utf-8")
d = json.load(f)
print(d)

# -------------json  函数传入返回 字典形式---------
class Man():def __init__(self,firstname,lastname):self.firstname = firstnameself.lastname = lastnamePerson = Man("海格力斯","王五")def func(obj):return {"first":obj.firstname,"last":obj.lastname}
s = json.dumps(Person,default=func,ensure_ascii=False)
print(s)

#-----------------字符串 字典 返回  对象------------
class Man():def __init__(self,firstname,lastname):self.firstname = firstnameself.lastname = lastname
dic = '{"firstname":"海格力斯","lastname":"王五"}'
def func(dic):return Man(dic["firstname"],dic["lastname"])s = json.loads(dic,object_hook=func)
print(s.firstname)