Python3 JSON data analysis

JSON (JavaScript Object Notation) is a lightweight data interchange format. It is based on a sub-set of ECMAScript.

Python3 json module can be used to encode and decode JSON data, which contains two functions:

• json.dumps (): encoding data.
• json.loads (): data is decoded.

In json codec process, python and json type of primitive types will be converted to each other, the specific transformation control as follows:

Python JSON encoded as a type conversion correspondence table:

JSON decodes the Python type conversion correspondence table:

json.dumps and json.loads examples

The following example demonstrates Python data structures into JSON:

#!/usr/bin/python3

import json

# Python 字典类型转换为 JSON 对象
data = {
    'no' : 1,
    'name' : 'w3big',
    'url' : 'http://www.w3big.com'
}

json_str = json.dumps(data)
print ("Python 原始数据：", repr(data))
print ("JSON 对象：", json_str)

Execute the above code output results:

Python 原始数据： {'url': 'http://www.w3big.com', 'no': 1, 'name': 'w3big'}
JSON 对象： {"url": "http://www.w3big.com", "no": 1, "name": "w3big"}

The results can be seen through the output, followed by the simple types by encoding its original repr () output is very similar.

Then the above example, we can convert a JSON-encoded string back to a Python data structure:

#!/usr/bin/python3

import json

# Python 字典类型转换为 JSON 对象
data1 = {
    'no' : 1,
    'name' : 'w3big',
    'url' : 'http://www.w3big.com'
}

json_str = json.dumps(data1)
print ("Python 原始数据：", repr(data1))
print ("JSON 对象：", json_str)

# 将 JSON 对象转换为 Python 字典
data2 = json.loads(json_str)
print ("data2['name']: ", data2['name'])
print ("data2['url']: ", data2['url'])

Execute the above code output results:

ython 原始数据： {'name': 'w3big', 'no': 1, 'url': 'http://www.w3big.com'}
JSON 对象： {"name": "w3big", "no": 1, "url": "http://www.w3big.com"}
data2['name']:  w3big
data2['url']:  http://www.w3big.com

If you want to deal with is the file instead of a string, you can usejson.dump () and json.load ()to encode and decode JSON data. E.g:

# 写入 JSON 数据
with open('data.json', 'w') as f:
    json.dump(data, f)

# 读取数据
with open('data.json', 'r') as f:
    data = json.load(f)

For more information, please refer to: https://docs.python.org/3/library/json.html