Oddbean new post about login | logout TIL python sqlite3 cursor objects are iterable, was always calling fetchone one by one 😭 (or fetchmany)
Does it fetchone for every iteration?
i think so (haven't checked the source, though)
C implementation: - cursor_iternext: https://github.com/python/cpython/blob/main/Modules/_sqlite/cursor.c#L1090 - cursor_fetchone_impl: https://github.com/python/cpython/blob/main/Modules/_sqlite/cursor.c#L1142 so yes, fetchone literally just calls next() on the iterator 🤷♀️ why did they even bother to add it ?!? i don't know, maybe it wasn't always this way, eg from what i remember iterators were much less common in python 2.x times
And then you created a loop yourself with a conditional in it for when you reached the last object? Never used sqlite3 much with python, only to get some stats from my nostr-rs-relay.
Ah did not read the fetchmany somehow 🤦♂️
i use sqlite3 a lot, it's great as application database--but in this case it's also for prying into nostr-rs-relay's database
yes, just fetchone in a loop usually
while True
rec = cursor.fetchone()
if rec is None:
break
which works the same i guess but it's more typing
if you're concerned about performance you'd also do this, but fetching a batch at the same time with fetchmany
there's also fetchall when you want to fetch everything, but don't expect so many it'd exhaust memory