[Python-Dev] requirements for moving __import__ over to importlib?

Brett Cannon brett at python.org
Wed Feb 8 22:08:29 CET 2012


On Wed, Feb 8, 2012 at 15:31, Terry Reedy <tjreedy at udel.edu> wrote:

> On 2/8/2012 3:16 PM, Brett Cannon wrote:
>
>> On Wed, Feb 8, 2012 at 14:57, Terry Reedy <tjreedy at udel.edu
>>    Would the following work? Treat a function as a 'loop' in that it
>>    may be executed repeatedly. Treat 'import x' in a function as what
>>    it is, an __import__ call plus a local assignment. Apply a version
>>    of the usual optimization: put a sys.modules-based lazy import
>>    outside of the function (at the top of the module?) and leave the
>>    local assignment "x = sys.modules['x']" in the function. Change
>>    sys.modules.__delattr__ to replace a module with a dummy, so the
>>    function will still work after a deletion, as it does now.
>>
>> Probably, but I would hate to force people to code in a specific way for
>> it to work.
>>
>
> The intent of what I proposed it to be transparent for imports within
> functions. It would be a minor optimization if anything, but it would mean
> that there is a lazy mechanism in place.
>
> For top-level imports, unless *all* are made lazy, then there *must* be
> some indication in the code of whether to make it lazy or not.


Not true; importlib would make it dead-simple to whitelist what modules to
make lazy (e.g. your app code lazy but all stdlib stuff not, etc.).
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-dev/attachments/20120208/ff7b231a/attachment.html>


More information about the Python-Dev mailing list