Explain
HTTP + JSON in 12 minutes
Your program asks a server for data. The server answers with a status code and a body (often JSON). When it breaks, you don’t guess—you print the receipts.
TL;DR
- Print the URL + status code every time.
- If status != 200: print a tiny slice of the body.
- JSON = dicts + lists. Print keys/lengths instead of guessing.
Status codes you’ll actually see
- 200: success
- 404: wrong URL, wrong region, wrong ID
- 429: rate limit (slow down, cache, retry later)
- 401: missing/invalid auth
- 403: auth present but expired/not allowed
JSON → Python types
JSON objects become dict. JSON arrays become list. “Nested data” is just “dicts inside
dicts inside lists”.
Tiny mental model
# JSON: {"items": [{"id": 1}, {"id": 2}]}
data = response.json()
print(type(data)) # dict
print(type(data['items'])) # list
print(data['items'][0]['id'])Print debugging: the minimum receipt
When a request fails, print just enough to be dangerous (to the bug).
Receipt template
print('URL:', url)
print('PARAMS:', params)
print('STATUS:', r.status_code)
if r.status_code != 200:
print('BODY:', r.text[:200])