Python解析json字符串，json字符串用法

json数据简介

json数据是一个轻量级的数据交换格式，采用完全独立于语言的文本格式，这些特性使json称为理想的数据交换语言，易于人阅读和编写，同时易于机器解析和生成。

json中的字符集必须是UTF-8，json中的字符串必须用双引号引起来。几乎所有语言都内置了解析json的库，JavaScript语言可以直接使用json。

json格式一般是“键值对”的格式，比如

键值对：{“firstName”:”Breet”,”lastName”:”MMM”,”email”:”XXX”}

再比如：

{

“programers”:[

{“firstName”:”Breet”,”lastName”:”MMM”,”email”:”XXX”},

{“firstName”:”Breet”,”lastName”:”MMM”,”email”:”XXX”}

],

“authors”:[

{“firstName”:”Breet”,”lastName”:”MMM”,”email”:”XXX”},

{“firstName”:”Breet”,”lastName”:”MMM”,”email”:”XXX”}

],

}

json的应用场景：web服务端的go数组->json字符串->网络传输->json字符串->反序列化->go数组->信息呈现给用户。

Python中解析json的库

import json
# 字典类型转换为json字符串
data = {"id": 1, 'name': 'sy', 'passwrd': ''}

print(type(data))
json_str = json.dumps(data)
print(type(json_str))
print(json_str)

print("*" * 20)

# json字符串转换为字典类型
json_str2 = '{"programers":[ {"firstName":"Breet","lastName":"MMM","email":"XXX"},'\
            '{"firstName":"Breet","lastName":"MMM","email":"XXX"}], ' \
            '"author": [{"firstName": "su", "lastName": "yang", "email": "XXX"},'\
            '{"firstName": "Breet", "lastName": "MMM", "email": "XXX"}]}'

print(type(json_str2))

data2 = json.loads(json_str2)

print(type(data2))
print(json_str2)
print(data2)

print('*' * 20)

# 将json数据写入文件，用文件传送

with open('aaa.json', 'w') as f:
    json.dump(data, f)

with open('aaa.json', 'r') as f:
    data3 = json.load(f)
    print(type(data3))
    print(data3)

运行结果：

<class 'dict'>

<class 'str'>

{"id": 1, "name": "sy", "passwrd": "123123"}

********************

<class 'str'>

<class 'dict'>

{"programers":[ {"firstName":"Breet","lastName":"MMM","email":"XXX"},{"firstName":"Breet","lastName":"MMM","email":"XXX"}], "author": [{"firstName": "su", "lastName": "yang", "email": "XXX"},{"firstName": "Breet", "lastName": "MMM", "email": "XXX"}]}

{'programers': [{'email': 'XXX', 'lastName': 'MMM', 'firstName': 'Breet'}, {'email': 'XXX', 'lastName': 'MMM', 'firstName': 'Breet'}], 'author': [{'email': 'XXX', 'lastName': 'yang', 'firstName': 'su'}, {'email': 'XXX', 'lastName': 'MMM', 'firstName': 'Breet'}]}

********************

<class 'dict'>

{'id': 1, 'name': 'sy', 'passwrd': '123123'}