vxgmichel
commented
1 month ago Hi @smheidrich, thanks for the suggestion :+1:
I think it would be useful too, feel free to create a PR if you feel like contributing to the project. The implementation is over there: https://github.com/vxgmichel/aiostream/blob/5e0547afcebfcb556e011df3c185f69794a187cb/aiostream/stream/combine.py#L49-L86
It relies on asyncio.gather which exposes a return_exceptions argument. However, I don't think we can use that since we still want to propagate the exception as soon as possible if it is not a StopAsyncIteration. Instead, we probably want to turn StopAsyncIteration into a sentinel with a dedicated function:
async_stop_iteration_sentinel = object()
if strict:
async def next_item(streamer):
try:
return await anext(streamer)
except StopAsyncIteration:
return async_stop_iteration_sentinel
else:
next_item = anext
[...]
try:
coros = builtins.map(next_item, streamers)
items = await asyncio.gather(*coros)
except StopAsyncIteration:
break
if strict:
if all(item == async_stop_iteration_sentinel for item in items):
break
if any(item == async_stop_iteration_sentinel for item in items):
raise ValueError
[...] Otherwise, I'll do it myself when I find the time :)
smheidrich
Python 3.10 introduced the
strictparameter for the built-inzipfunction, which, when set toTrue, can help spot bugs by raising an exception when the supplied iterables turn out to have different lengths (i.e. when one raisesStopIterationafter fewer iterations than the others).I think it would be useful if aiostream's
zipfunction supported this parameter as well.Extra context: The
strictparameter of Python's built-inzipturned out to be useful enough that linters like Ruff or flake8 with the bugbear plugin even have a rule to complain when you neither use it nor explicitly disable it by settingstrict=False.