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”