APIs, JSON, and Data

Read structured data and prepare for real HTTP API work.

Why this matters

Modern Python scripts and services often exchange JSON with APIs and other systems.

Start with the idea

JSON represents objects, arrays, strings, numbers, booleans, and null values. Python can decode JSON into dictionaries and lists, then your code should validate the shape it expects.

IdeaUnderstand the purpose

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CodeRun the smallest example

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PracticeChange it yourself

SubjectVision learning pattern: understand the idea before memorizing syntax.

Small working example

Run this example first. Do not change several things at once; confirm the basic behavior, then experiment.

import json

payload = '{"name": "Maya", "active": true}'
data = json.loads(payload)
print(data["name"])

Expected output

Maya

What to notice

The example is intentionally small. Focus on the chapter’s main idea before adding extra syntax or framework code.

Common beginner mistake

Mistake

Assuming external API responses always contain every field and correct type.

Better approach

Validate required fields, handle error responses, timeouts, and malformed data explicitly.

Quick recap

JSON maps naturally to common Python structures.
External data is untrusted input.
API code needs error and timeout handling.

Try it yourself

These are deliberately small. If you can complete them without copying the example, you are ready to continue.

Decode a small JSON array.
Safely read an optional field from decoded data.