[Fwd: Re: Calling function from another module]

[craf]

--------- Mensaje reenviado --------
> De: Peter Otten <__peter__ at web.de>
> Para: python-list at python.org
> Asunto: Re: Calling function from another module
> Fecha: Thu, 16 Dec 2010 13:16:30 +0100
> Grupos de noticias: comp.lang.python
> 
> craf wrote:
> 
> > Hi.
> > 
> > The query code is as follows:
> > 
> > ------------------------------------------------------
> > import Tkinter
> > import tkMessageBox
> > 
> > 
> > class App:
> >     def __init__(self, master):
> >         master.protocol("WM_DELETE_WINDOW",quit)
> > 
> > 
> > def quit():
> >     if tkMessageBox.askyesno('','Exit'):
> >         master.quit()
> > 
> > 
> > master =Tkinter.Tk()
> > app = App(master)
> > master.mainloop()
> > -------------------------------------------------------
> > 
> > As you can see, when I run and close the main window displays
> > a text box asking if you want to quit, if so, closes
> > application.
> > 
> > Question:
> > 
> > Is it possible to define the quit() function in another separate
> > module?.
> > I tried it, but it throws the error that the global name
> > 'master' is not defined.
> 
> You can have the modules import each other and then access the master as
> <module>.master where you'd have to replace <module> with the actual name of 
> the module, but that's a bad design because 
> 
> (1) you create an import circle
> (2) functions relying on global variables already are a bad idea
> 
> Your other option is to pass 'master' explicitly and then wrap it into a 
> lambda function (or functools.partial):
> 
> $ cat tkquitlib.py
> import tkMessageBox
> 
> def quit(master):
>     if tkMessageBox.askyesno('','Exit'):
>         master.quit()
> 
> 
> $ cat tkquit_main.py
> import Tkinter
> 
> import tkquitlib
> 
> class App:
>     def __init__(self, master):
>         master.protocol("WM_DELETE_WINDOW", lambda: tkquitlib.quit(master))
> 
> master = Tkinter.Tk()
> app = App(master)
> master.mainloop()
> 
> Peter

Hi Peter.

¡Right!. Your example can separate the creation of the interface to the
code execution. Thanks for your time.

Regards

Cristian