How to Work with JSON in Python: json Module Complete Guide

Python's json Module

Python includes a built-in json module that handles JSON serialization and deserialization. No installation required.

Parse JSON from a String

import json

data = json.loads('{"name": "Alice", "age": 30}')
print(data['name'])  # Alice
print(type(data))    # dict

Convert Python to JSON String

import json

obj = {'name': 'Alice', 'age': 30, 'active': True}
json_str = json.dumps(obj, indent=2)
print(json_str)

Read JSON from a File

import json

with open('data.json', 'r') as f:
    data = json.load(f)
print(data)

Write JSON to a File

import json

data = {'users': [{'id': 1, 'name': 'Alice'}]}
with open('output.json', 'w') as f:
    json.dump(data, f, indent=2)

Handling Dates and Custom Types

from datetime import datetime
import json

# Serialize datetime
json.dumps({'created': datetime.now().isoformat()})

# Custom encoder
class DateEncoder(json.JSONEncoder):
    def default(self, obj):
        if isinstance(obj, datetime):
            return obj.isoformat()
        return super().default(obj)

json.dumps({'ts': datetime.now()}, cls=DateEncoder)

json.dumps() Options Reference

Use the complete Python JSON guide at jsondecode.com for more examples.