When sending HTTP requests, the Content-Type header must match the data format being sent:

JSON Format:
Content-Type: application/json
Request body: {"mobile_phone":"13164761466","pwd":"123456789"}
Usage: json=json_data

Form Data Format:
Content-Type: aplication/x-www-form-urlencoded
Request body: mobile_phone=13164761466&pwd=123456789
Usage: data=form_data

JSON Serialization in Python

Serialization converts Python data structures (dictionaries, lists) into JSON-formatted strings for use by other systems.

Converting Dictionary to JSON String:

import json

sample = {'username': 'john', 'status': None, 'is_active': False, 'is_admin': True}
result = json.dumps(sample)
print(result)

Output:

{"username": "john", "status": null, "is_active": false, "is_admin": true}

Key Type Conversions:

• None becomes null
• True becomes true
• False becomes false
• Single quotes become double quotes
• Tuples and lists both convert to arrays

Example with Multiple Types:

import json

data = {'items': [1, 2, 'a'], 'coordinates': (1, 2), 'value': None, 'flag': False}
print(json.dumps(data))

Output:

{"items": [1, 2, "a"], "coordinates": [1, 2], "value": null, "flag": false}

JSON Deserialization in Python

Deserialization converts JSON strings back into Python dictionaries. Note that JSON keys must use double quotes.

import json

json_string = '{"name": "alice", "age": 25, "active": true}'
parsed_data = json.loads(json_string)
print(parsed_data)

Output:

{'name': 'alice', 'age': 25, 'active': True}

JavaScript JSON Methods Comparison

JavaScript JSON.parce():
Used when receiving JSON data from Python. It parses JSON strings into JavaScript objects.

JSON.parse('{"items": [1, 2, "a"], "result": null}')

JavaScript JSON.stringify():
Used when sending data to Python. It converts JavaScript objects into JSON strings.

JSON.stringify({name: 'bob', value: null})

This JSON string can then be parsed by Python's json.loads():

import json

js_output = '{"name": "bob", "value": null}'
python_data = json.loads(js_output)
print(python_data)

Output:

{'name': 'bob', 'value': None}

Advanced json.dumps() Parameters

Handling Non-ASCII Characters:
By default, json.dumps() escapes non-ASCII characters. Use ensure_ascii=False to preserve them.

import json

data = {'name': 'li', 'flag': True, 'greeting': 'hello'}
print(json.dumps(data))

Output (with default settings):

{"name": "li", "flag": true, "greeting": "\u4f60\u597d"}

Output (with ensure_ascii=False):

{"name": "li", "flag": true, "greeting": "hello"}

Compact Output with separators:
Remove extra whitespace using the separators parameter.

import json

data = {'name': 'li', 'flag': True, 'message': 'hello'}
print(json.dumps(data, ensure_ascii=False, separators=(",", ":")))

Output:

{"name":"li","flag":true,"message":"hello"}