runtimequestion 389 Async Python · hard
Follow next-page links, retrying busy pages
An earthquake feed is split into pages; each page's JSON has "features" and a "next" URL (null on the last page). Pages must be read in order, because each one tells you the next. Write all_features(transport, first_url, retries): follow the links, retrying a page that answers 503 up to retries extra times (waiting 0.5 s between tries), and return every feature's id in order. A page that still fails, or answers anything else that isn't 200, raises HTTPStatusError.
Simulated: this runs against results recorded on real Python.
Coroutine
async def all_features(transport, first_url, retries)Pages
{"features": [...], "next": url or None}Returnsthe
id of every feature, page by pageErrors503 → wait 0.5 s and retry (at most
retries retries per page); other non-200 statuses, or a 503 after the last retry → raise_for_status()