Define type of 'module' object that is imported

[robert]

Zachary Pincus wrote:

> Hi folks,
> 
> I'm sure this has come up before, but the search terms I've been  using 
> are so non-specific that I can't get any traction on Google.
> 
> Here's my question:
> I have written a subclass of ModuleType that handles lazy loading of  
> some slow resources. I would like a given module to be created as an  
> instance of that particular subclass on import, so that if I do:
> 
> import foo
> type(foo)
> 
> I get <type 'myModule'> instead of <type 'module'>.
> 
> Is there any way to effect this? Something like __metaclass__ = ...  but 
> at the beginning of a module instead of at the beginning of a class?

Would be interesting to know about the motivation. Is foo just your own 
module or "any" module.

* you can replace __import__
* you can set sys.modules['foo']=mymod   (in sitecustomize.py ? )
* your module can be a class instance as well in newer pythons (2.2+?);
   => you can set sys.modules['foo']=Foo()   # Foo having properties ...
* simply import certain expensive modules only ad-hoc
* maybe you don't need it as module at all, but an instance. or you 
avoid pre-computing things in global namespace.
...


robert

---

PS:

In the Python standard lib there are some slow importing monsters. The 
worst is now urllib2 needing up to a second to import.
Thats because there is a questionable style of importing all kind of 
expensive stuff that _might_ be useful in advance as if we had C-style 
compiler #include-s. Yet Python allows 
best-amongst-most-programming-languages dynamic modularization of code 
by local/late imports. Most time you'll see, that the imported modules 
are anyway only needed in very few locations. the pychecker helps.

See rejected:
http://sourceforge.net/tracker/index.php?func=detail&aid=1053150&group_id=5470&atid=305470

Meanwhile the cookielib is also amongst those urllib2 inhabitants - and 
its the slowest towards my profile runs. I've regular private patches on 
my production python installation to get apps (startup) fluid.

Maybe that rejected sf request should be re-opened, and a request put to 
optimize the python lib for late dynamic import's - at least in 
locations where (regardign a profiler inspection) it pays off well on 
low coding costs ?