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Manuals / Python / Ch 9

D · HTTPIntermediate45 min read

9. httpx for API calls

Python · 52 pages source format

Sync httpx for scripts; async httpx pairs with Playwright later. Status codes, JSON bodies, timeouts, basic auth headers.

What you'll learn

  • httpx.Client
  • GET/POST
  • Status codes
  • Timeouts and errors

GET request

httpx.get(url) or with Client() for connection reuse. response.raise_for_status() on errors.

import httpx

resp = httpx.get("https://jsonplaceholder.typicode.com/users", timeout=10.0)
resp.raise_for_status()
users = resp.json()
assert len(users) == 10

Do this now

Fetch jsonplaceholder users. Assert 200 and len(users) == 10.

Clear?

POST and headers

client.post(url, json={...}) sends JSON body. headers={"Authorization": "Bearer ..."} when needed.

Do this now

POST a new todo to jsonplaceholder. Print returned id.

Clear?

Test API helpers

Extract fetch_users(client) → list. Unit test with httpx mock or fixture JSON — not live network.

Do this now

Write fetch_users using httpx. Test parsing with fixture file.

Pro tip. Playwright path uses httpx for API-only tests — this chapter prepares you for that.

Clear?

Checklist