pickle序列化与反序列化 + eval说明

import pickle

# #1、从文件中读取pickle格式
with open('egon.json','rb') as f:
    pkl=f.read()
#2、将json_str转成内存中的数据类型
dic=pickle.loads(pkl)
print(dic['a'])

#1和2可以合作一步
with open('db.pkl','rb') as f:
    dic=pickle.load(f)

print(dic['a'])

# pickle 的序列化
import json,pickle

s={1,2,3}
# json.dumps(s)
pickle.dumps(s)

import pickle

dic={'a':1,'b':2,'c':3}

# 1 序列化
pkl=pickle.dumps(dic)  # 字典序列化后变成字节，不是字符串
print(pkl,type(pkl))
# #2 写入文件
with open('db.pkl','wb') as f:  # 对应的写入文件就应该是wb模式写入
    f.write(pkl)

# 1和2可以合作一步
with open('db.pkl','wb') as f:
    pickle.dump(dic,f)

# json格式不能识别单引号，全都是双引号

import json

with open('db1.json','rt',encoding='utf-8') as f:
    json.load(f)

json.loads('{"name":"egon"}')

import json
print(json.loads("{'name':'egon'}"))  #会报错，json文件里不存在单引号。反序列化对象里面不能有单引号

with open('db.json','wt',encoding='utf-8') as f:
    l=[1,True,None]
    json.dump(l,f)

# 用json反序列化
with open('db.json','rt',encoding='utf-8') as f:
    l=json.load(f)
    print(l)

# 用eval反序列化：eval只是单纯的将文件里的字符串运行变成对应的数据类型，而不会把json文件里卖弄的true，null转换成True，None
with open('db.json','rt',encoding='utf-8') as f:
    s=f.read() #s ='[1, true, null]'
    dic=eval(s) #eval('[1, true, null]')
    print(dic['name'])