[Python-ideas] making a module callable

[Ethan Furman]

On 11/20/2013 12:14 PM, Eric Snow wrote:
>
> Sticking something into sys.modules to replace the currently executing
> module is indeed a hack.  The import system accommodates this not by
> design (unless someone is willing to come forward and admit guilt
> <wink>) but mostly as an incidental implementation artifact of the
> import machinery from many releases ago. [1]

Actually, it is intentional.  An excerpt from https://mail.python.org/pipermail/python-ideas/2012-May/014969.html

>  There is actually a hack that is occasionally used and recommended:
>  a module can define a class with the desired functionality, and then
>  at the end, replace itself in sys.modules with an instance of that
>  class (or with the class, if you insist, but that's generally less
>  useful). E.g.:
>
> # module foo.py
>
>   import sys
>
>   class Foo:
>       def funct1(self, <args>): <code>
>       def funct2(self, <args>): <code>
>
>   sys.modules[__name__] = Foo()
>
> This works because the import machinery is actively enabling this
>  hack, and as its final step pulls the actual module out of
>  sys.modules, after loading it. (This is no accident. The hack was
>  proposed long ago and we decided we liked enough to support it in
>  the import machinery.)

--
~Ethan~