#将对象转换字符串,存储到文件中(dump)
import json
dic = {1:2,3:4,5:6}
f = open(‘a1.txt‘,‘w‘,encoding=‘utf-8‘)
s = json.dump(dic,f)
print(s)
运行结果:
文件中已填写的内容:{"1": 2, "3": 4, "5": 6}

#将文件的字符串转换成原格式输出(load)
f = open(‘a1.txt‘,‘r‘,encoding=‘utf-8‘)
s1 = json.load(f)
print(type(s1),s1)
运行结果:
<class ‘dict‘> {‘1‘: 2, ‘3‘: 4, ‘5‘: 6}

将对象转换成字符串
import json
lst = [1,2,3,4]
s = json.dumps(lst)
print(type(s),s)
运行结果:
<class ‘str‘> [1, 2, 3, 4]

#将字符串转换成对象
lst = [1,2,3,4]
s1 = json.loads(s)
print(type(s1),s1)
运行结果:
<class ‘list‘> [1, 2, 3, 4]

#将对象转换为文件(内容是字节,看不懂的字节)
import pickle
f = open(‘a2.py‘,‘wb‘)
dic = {1:2,3:4}
s = pickle.dump(dic,f)
print(s)
运行结果:文件已填写内容,但是是一串看不懂的字节

#将字节文件转换成对象
f1 = open(‘a2.py‘,‘rb‘)
s1 = pickle.load(f1)
print(s1)
运行结果:{1: 2, 3: 4}

#将对象转换成字节
import pickle
dic = {1:2,3:4}
s = pickle.dumps(dic)
print(s)
运行结果:b‘\x80\x03}q\x00(K\x01K\x02K\x03K\x04u.‘

#将字节转换成对象
s1 = pickle.loads(s)
print(s1)
运行结果:
{1: 2, 3: 4}

import shelve
f = shelve.open(‘a2‘) 
#创建了3个文件,a2.bak(是备份),这三个文件的内容都不要有任何的修改
f[‘name‘] = ‘alex‘ #增加键值对
f[‘age‘] = 18
print(f[‘name‘])
打印结果:alex

##实现修改name的操作
import shelve
f = shelve.open(‘a2‘,writeback=True) 
f[‘name‘] = ‘baoyuan‘
print(f[‘name‘])