Loading just in time

[Scott David Daniels]

D'Arcy J.M. Cain wrote:
> I am trying to create a utility module that only loads functions when
> they are first called rather than loading everything.  I have a bunch
> of files in my utility directory with individual methods and for each I
> have lines like this in __init__.py:
> 
> def calc_tax(*arg, **name):
>     from calc_tax import calc_tax as _func_
>     calc_tax = _func_
>     return _func_(*arg, **name)
> ...

Well, you may well be "mired in premature optimization," but you _could_
do the following (you'll need to evaluate whether it addresses your
issues).

     def calc_tax(*arg, **kwargs):
         from calc_tax import calc_tax
         globals()['calc_tax'] = calc_tax
         return calc_tax(*arg, **kwargs)

But if you are terrifyingly clever, (or have enough motive*), you can
define a function, '_remote', So that your __init__.py contains:
       <some magic>
       ...
       _remote('some_tax')
       _remote('other', 'frogs')
       ...

* The pythonic "enough motive" is how redundant your "__init__.py"
looks.  The "DRY" (Don't Repeat Yourself) principle comes into effect.
The more your source looks like boilerplate, the more you should itch
to  replace the boilerplate.

--Scott David Daniels
Scott.Daniels at Acm.Org