Victor Stinner wrote: > 2014-07-20 18:50 GMT+02:00 Antoine Pitrou <anto...@python.org>: >> Have you tried modifying importlib's _bootstrap.py to use scandir() >> instead of listdir() + stat()? > > IMO the current os.scandir() API does not fit importlib requirements. > importlib usually wants fresh data, whereas DirEntry cache cannot be > invalidated. It's probably possible to cache some os.stat() result in > importlib, but it looks like it requires a non trivial refactoring of > the code. I don't know importlib enough to suggest how to change it.
The data is completely fresh at the time it is obtained, which is identical to using stat(). There will always be a race-condition between looking and doing, which is why we still use exception handling on actions. > By the way, DirEntry constructor is not documented in the PEP. Should > we document it? It might be a way to "invalidate the cache": > > entry = DirEntry(os.path.dirname(entry.path), entry.name) > > Maybe it is an abuse of the API. A clear_cache() method would be less > ugly :-) But maybe Ben Hoyt does not want to promote keeping DirEntry > for a long time? DirEntry is a convenient way to return a tuple without returning a tuple, that's all. If you want up to date info, call os.stat() and pass in the path. This should just be a better (and ideally transparent) substitute for os.listdir() in every single context. Personally I'd make it a string subclass and put one-shot properties on it (i.e. call/cache stat() on first access where we don't already know the answer), which I think is close enough to where it's landed that I'm happy. (As far as bikeshedding goes, I prefer "_DirEntry" and no docs :) ) Cheers, Steve _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
