Get importer module from imported module

[Duncan Booth]

dody suria wijaya wrote:

> "import a" inside b would not solve the problem, since there
> are many "module a" and module b does not know beforehand
> which module had imported it.

Ok, I understand now what you are trying to achieve, but there isn't any 
concept relating a module back to the first module which tried to import 
it. Instead you'll have to specify the relationship yourself.

How about this:

> #Module c
import sys
food_no = sys.argv[1]
m = __import__(food_no)
goodie = b.Salty(m)

> #Module b
...
def Salty(module):
    class Food(SaltyMixIn,module.Main): pass
    return Food()
...

In fact, it looks like the importing isn't really something module c should 
be concerned about. I haven't tested the following code (so it will have 
bugs), but it should give you some ideas. It remembers classes it has 
created so as not to duplicate them, and it also gives each class a 
sensible name.

> #Module c
import sys
food_no = sys.argv[1]
goodie = b.Salty(food_no)

> #Module b
...
import new
Classes = {}

def makeFood(classname, food, mixin):
    m = __import__(food)
    main = m.Main
    if (mixin, main) in Classes:
      return Classes[mixin, main]()

    newclass = new.classobj(classname + '_' + food, (mixin, main), {})
    Classes[mixin, main] = newclass
    return newclass
    

def Salty(food):
    return makeFood('Salty', food, SaltyMixIn)
...