[Python-Dev] requirements for moving import over to importlib? (original) (raw)

PJ Eby pje at telecommunity.com
Thu Feb 9 02:28:56 CET 2012

On Wed, Feb 8, 2012 at 4:08 PM, Brett Cannon <brett at python.org> wrote:

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

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.).

There's actually only a few things stopping all imports from being lazy. "from x import y" immediately de-lazies them, after all. ;-)

The main two reasons you wouldn't want imports to always be lazy are:

  1. Changing sys.path or other parameters between the import statement and the actual import
  2. ImportErrors are likewise deferred until point-of-use, so conditional importing with try/except would break. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.python.org/pipermail/python-dev/attachments/20120208/ca56fb26/attachment.html>

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