Python3 JSON Data Parsing

JSON (JavaScript Object Notation) is a lightweight data interchange format.

If you don't yet understand JSON, you can first read ourJSON Tutorial。

Python3 can use the json module to encode and decode JSON data. It contains two functions:

  • json.dumps(): Encode data.
  • json.loads(): Decode data.

During the json encoding/decoding process, Python's native types and json types are converted to each other. The specific conversion correspondences are as follows:

Python encoding to JSON type conversion correspondence table:

Python JSON
dict object
list, tuple array
str string
int, float, int- & float-derived Enums number
True true
False false
None null

JSON decoding to Python type conversion correspondence table:

JSON Python
object dict
array list
string str
number (int) int
number (real) float
true True
false False
null None

json.dumps and json.loads examples

The following example demonstrates converting Python data structures to JSON:

Example (Python 3.0+)

#!/usr/bin/python3 import json # Python dictionary type converted to JSON object data = { 'no' : 1, 'name' : 'Example', 'url' : 'https://www.example.com' } json_str = json.dumps(data) print ("Python original data:", repr(data)) print ("JSON object:", json_str)

Executing the above code outputs the following result:

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

From the output result, it can be seen that after encoding, simple types are very similar to their original repr() output.

Continuing from the above example, we can convert a JSON-encoded string back into a Python data structure:

Example (Python 3.0+)

#!/usr/bin/python3 import json # Python dictionary type converted to JSON object data1 = { 'no' : 1, 'name' : 'Example', 'url' : 'http://www.example.com' } json_str = json.dumps(data1) print ("Python original data:", repr(data1)) print ("JSON object:", json_str) # Convert JSON object to Python dictionary data2 = json.loads(json_str) print ("data2['name']: ", data2['name']) print ("data2['url']: ", data2['url'])

Executing the above code outputs the following result:

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

If you are dealing with a file rather than a string, you can usejson.dump()andjson.load()to encode and decode JSON data. For example:

Example (Python 3.0+)

# Write JSON data with open('data.json', 'w') as f: json.dump(data, f) # Read data 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 Other extensions