json，pickle，shelve序列化

import json
 
a = [{"a":"b"}]
jd = json.dumps(a) #序列化，就是对象通过内存能够存储和传输的过程
with open("json.txt","w") as wo: #创建句柄
    wo.write(jd)

import json
 
with open("json.txt","r") as pe:
    pr = pe.read()   #读取json.txt类容
    jl = json.loads(pr)  #反序列化  把变量内容从序列化的对象重新读到内存里称之为反序列化
    print(jl)

import json
 
with open("json.txt","r") as pe:
    # pr = pe.read()   #读取json.txt类容
    # jl = json.loads(pr)  #反序列化  把变量内容从序列化的对象重新读到内存里称之为反序列化
    jl = json.load(pe)
    print(jl)

import json
 
with open("json.txt","r") as pe:
    # pr = pe.read()   #读取json.txt类容
    # jl = json.loads(pr)  #反序列化  把变量内容从序列化的对象重新读到内存里称之为反序列化
    jl = json.load(pe)
    print(jl)

-------------------------------------------------------pickle-----------------------------------------------------------------------------------

b = {"a":"c","g":"f"}
pic = pickle.dumps(b)
#创建句柄
with open("pickle","wb") as wp:
    wp.write(pic)

import pickle
 
with open("pickle","rb",) as ws:
    print(pickle.loads(ws.read()))

--------------------------------------------------------------------------------------------------------------------------

import shelve
 
#创建句柄
she = shelve.open("wenjian")
she["s"] = {"a":"b","f":"g"}  #添加内容
#----------------------------------------------------
she = shelve.open("wenjian")
print(she.get("s"))   #读取信息
 
#----------------------------------------------------
b = {"a":"b","c":"d"}
print(b.get("a"))
print(b.get("d")) #None  如果字典中没有这个“键”后面也没有值就显示None
print(b.get("e","f"))  # f  如果字典中没有这个“键”就显示后面的“值”
print(b.get("a","hh"))  # b  如果字典中有这个“键”，就显示字典的“值”