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\': \'123123\'}

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\'}