Josh Rosenberg added the comment: +1; I've had several cases where I'd have used something like this (for the exact purpose mentioned, to destructively consume an input iterable). I don't think it's more or less useful than the sentinel version, which is convenient for iterating a file by blocks instead of by line, e.g.:
from functools import partial with open('...', 'rb') as f: for block in iter(partial(f.read, 4096), b''): ... But it would still nice to be able to destructively iterate sequences, particularly in CPython, where doing it at the C level can get you atomicity without relying on anything beyond the GIL (and without wrapping infinite while loops in try/except: pass blocks, which is pointlessly verbose). One issue: You can't just make the second argument allow exception types as well, since it's possible (however unlikely) for an exception type to be a legitimate return type from a function. Making it keyword only would solve that problem though. ---------- nosy: +josh.rosenberg _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue20663> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com