name of client module

[Jeff Schwab]

Nick Stinemates wrote:
> Jeff Schwab wrote:
>> Q1: When a module is imported, is there any way for the module to 
>> determine the name of the client code's module?
>>   
> Why would you ever want to do this?
>> Q2: My understanding is that the code in a module is executed only on 
>> the first import of that module.  Is there any way to have a hook 
>> invoked on subsequent imports, and for that hook (as in Q1) to determine 
>> the name of the client module?
>>   
> Why would you ever want to do this?

So that the imported module can implement functions that return 
information about the client module, as a form of introspection. 
Suppose I want to know whether I'm the main module, and I don't want to 
write __name__ == '__main__'; it would be nice if I could import a 
module and call a method to tell me whether I'm __main__:

     import modinfo

     if modinfo.main():
         print("Hello, world")

> I don't really understand why you wouldn't want to do the following:
> 
> import foo
> foo.exec()

I'm not saying I don't want to do that.  I'm saying that, in addition to 
what you've written, I want foo to know it's being imported, and by whom.