[Python-ideas] Idea: Lazy import statement

Greg Ewing greg.ewing at canterbury.ac.nz
Tue Oct 14 06:56:53 CEST 2008

Josiah Carlson wrote:

> How is this mechanism supposed to behave in the presence of things like...
>     # baz.py
>     from foo lazy import bar
>     def fcn():
>         return bar.obj(...)

I would say "don't do that".

If bar is always used within the baz module, there's no
reason to lazily import it -- just use an ordinary import.

If you're trying to achieve a conditional import, use
an ordinary import that's executed conditionally, e.g.

   if moon_is_full:
     from foo import bar

Then py2exe will notice the potential for importing
the foo module and include it.

The only time you should use a lazy import is in the
situation I described, i.e. you're importing things
solely to re-export them for other modules that may
want to use them. Any module that actually uses something
itself, even if only potentially, should use a normal


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