List:
I have an idea for an abstract factory that parameterizes the factory
with an input module.
The general ideom can be expressed thus:
class ThingFactory(object):
def CreateThisThing() : return ThisThing()
def CreateThatThing() : return ThatThing()
def CreateTheOtherThing() : return TheOtherThing()
With subclasses:
class HerThingFactory(ThingFactory):
def CreateThisThing() : return HerThisThing()
# etc
You'd invoke it in the usual way:
ThingClient(Factory=ThingFactory)
And Thing client would refer to:
ThingFactory.CreateThisThing()
Now, Pythonically speaking, as the envisioned application uses only one
ThingFactory at a time, I'd ordinarily want to just load a module
(HisFactory, HerFactory, KidsFactory, YadaYadaYadaFactory) that
implements the expected interface--in this case, supplying the CreateX
methods.
What I'd like is to do something like this:
factoryFile = sys.argv[1] # we assume that argv[1] implements a
# correct ThingMaker interface.
# A Miracle Occurs Here
UseFactory(factoryObject)
Where UseFactory looks like:
def UseFactory(factoryObject):
factoryObject.CreateThisThing() # returns the kind of thing
Rather a lot of preamble to learn what I'm trying to do.
Anywho, my problem is with the whole Miracle thing.
I've tried using __import__:
a = 'HerFactory'
__import(a)
Which returns:
<module 'HerFactory' from 'HerFactory.py'>
But after that I can't access the members.
Clearly I'm missing a step or seventeen.
What's the best way to do this?
Thanks
Charles
--
http://mail.python.org/mailman/listinfo/python-list
