[Python-Dev] possibility of shaving a stat call from imports

[Nick Coghlan]

On 19 Oct 2013 02:56, "Brett Cannon" <brett at python.org> wrote:
>
> importlib.machinery.FileFinder does a stat call to check if a path is a
file if the package check failed. Now I'm willing to bet that the check is
rather redundant as the file extension should be a dead give-away that
something in a directory is a file and not some non-file type. The import
would still fail even if this is the case in the loader when attempting to
read from the file, but it happens a little later and it means finders
would be more permissive in claiming they found a loader.
>
> Does anyone see a good reason not to take the more optimistic route in
the finder? As I said, the only thing I see breaking user code is if they
have a directory or something named spam.py and so the finder claims it
found a module when in fact it didn't and thus stopping the search for the
module from continuing.

I suspect anything that makes weird import edge case failures harder to
debug than they already are won't be worth it.

My opinion would likely differ if the speed up on offer was dramatic, but
it sounds like that isn't the case.

(Also, customised Python builds may have additional extensions that are at
higher risk of being used on directory names)

Cheers,
Nick.

>
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