JSON Handling

What JSON is

JSON is a simple text format for data. It looks like Python dictionaries and lists, but it is just text.

Converting JSON to Python (loads)

json.loads() takes a JSON string and returns Python data.

python
import json
text = '{"name": "Lina", "age": 28}'
data = json.loads(text)
print(data["name"])

Converting Python to JSON (dumps)

json.dumps() turns Python data into a JSON string.

python
data = {"name": "Lina", "age": 28}
text = json.dumps(data)
print(text)

Reading JSON from a file (load)

python
with open("data.json", "r") as f:
    data = json.load(f)

Writing JSON to a file (dump)

python
with open("data.json", "w") as f:
    json.dump(data, f, indent=2)

Common mistakes to avoid

• Using single quotes in JSON (JSON requires double quotes).
• Forgetting that JSON only supports basic types (no tuples or sets).
• Treating JSON as a Python dict without calling json.loads() or json.load().

What you should understand after this lesson

• The difference between load(s) and dump(s).
• How to read and write JSON files.
• The basic limits of JSON types.