云学编程的21天—【微软官方python入门教程 P38-P39笔记】2021-11-21 P38-P39 JSON的三种结构

本文介绍了JSON这种标准数据格式的基础知识，包括其三种主要结构：键值对、嵌套键值对和键值列表。通过使用linting工具格式化，可以更方便地阅读JSON。提取JSON中的值需要指定键名，对于嵌套结构，还需指定子键名。对于列表结构，可以使用循环获取所有值。此外，可以从字典创建JSON对象，但记得先导入json模块。

Many web services return data as JSON

JSON is a standard data format that can be intimidating at first glance.

Using a linting tool to format JSON makes it easier to read

JSON contains key pairs

"kay":"value"

{"kay":{"subkey0":"subvalue0","subkey1":"subvalue1,....."}}

{"key":[listvalue0,listvalue1,listvalue2,...]}

Basically what you'll notice is there's a pattern to how the JSON data looks.

To retrieve the value from a "key":"value" request the key name

print(results['requestId'])

To request a value from a {"kay":{"subkey0":"subvalue0","subkey1":"subvalue1,....."}} specify the key name and the subkey name

print(results['color']['dominantcolorbackground'])

To request a value from a {"kay":{"subkey0":"subvalue0","subkey1":"subvalue1,....."}} specify the keyname and index position of the value to retrieve

print(results['description']['tags'][0])

Use a loop to retreve all values from a {"key":[listvalue0,listvalue1,listvalue2,...]}

for item in results['description']['tags']:
    print(item)

You can create "key":"value"JSON objects from a dictionary

#Create a dictionary object
person_dict = {'first':'Christopher','last':'Harrison'}
#Add additional key pairs as needed to dictionary
person_dict['City']='Seattle'

#Convert dictionary to JSON object
person_json = json.dumps(person_dict)
print(person_json)

注意先要import json

P39实操：

她视频里给的地址没权限，有时间自己找一个试试