Skip to main content

55. Working with JSON Files

1. Introduction​

JSON (JavaScript Object Notation) is a lightweight format for storing and exchanging data. Python provides the json module.

2. Writing JSON​

import json

data = {"name": "Alice", "age": 25}
with open("data.json", "w") as f:
    json.dump(data, f)

3. Reading JSON​

with open("data.json") as f:
    obj = json.load(f)
print(obj)

4. Converting Between JSON and Strings​

s = json.dumps(data)
print(s)
obj = json.loads(s)
print(obj)

5. Handling Non-Serializable Data​

Custom objects need conversion before JSON encoding.

from datetime import datetime
data = {"time": datetime.now().isoformat()}

6. Pretty Printing JSON​

print(json.dumps(data, indent=4))

7. Next Steps​

✅ You now know how to read and write JSON in Python.
Next: Configuration files.