[Python-Dev] Updates to PEP 471, the os.scandir() proposal (original) (raw)

Ben Hoyt benhoyt at gmail.com
Wed Jul 9 17:35:26 CEST 2014

One issue with option #2 that I just realized -- does scandir yield the entry at all if there's a stat error? It can't really, because the caller will expect the .lstat attribute to be set (assuming he asked for type='lstat') but

it won't be. Is effectively removing these entries just because the stat failed a problem? I kind of think it is. If so, is there a way to solve it with option #2? Leave it up to the onerror handler. If it returns None, skip yielding the entry, otherwise yield whatever it returned -- which also means the error handler should be able to set fields on the DirEntry: def logerr(exc, entry): logger.warn("Cannot stat {}".format(exc.filename)) entry.lstat.stsize = 0 return True

This is an interesting idea, but it's just getting more and more complex, and I'm guessing that being able to change the attributes of DirEntry will make the C implementation more complex.

Also, I'm not sure it's very workable. For log_err above, you'd actually have to do something like this, right?

def log_err(exc, entry): logger.warn("Cannot stat {}".format(exc.filename)) entry.lstat = os.stat_result((0, 0, 0, 0, 0, 0, 0, 0, 0, 0)) return entry

Unless there's another simple way around this issue, I'm back to loving the simplicity of option #1, which avoids this whole question.

-Ben

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