Need help with Classes in Python

I'm making a program that imports a custom widget that is a class (it inherits from the Tkinter Frame widget). It all works great until I get to binding. To reduce confusion we'll call the main application app, the module it's importing the widget from lib, and the widget that's being imported into app will be called cwid.

Basically I need to somehow reference a function in app, so that it may be bound to my widget in lib.

The function I'm trying to bind a widget within cwid to is element_click (The function element_click is in app.):

lambda event: element_click(event, elementinfo[3])

So the binding would look something like this in lib (element is a canvas widget within cwid)

element.bind('<ButtonRelease-1>', lambda event: element_click(event, elementinfo[3]))

The above line wont work however seeing as element_click is in app. So I tried a work around which doesn't seem to be working.

import app

loc = app.EOG

element.bind('<ButtonRelease-1>', lambda event: loc.element_click( event, elementinfo[3]))

When I try the above I get the following error:

TypeError: unbound method element_click() must be called with EOG instance as first argument (got Event instance instead)

EOG is a class in app which contains element_click.

Also, all of the above开发者_运维百科 bits of code are snippets.

EDIT:

Tried loc = app.EOG(), and go the following error:

AttributeError: EOG instance has no attribute '__nonzero__'

I think you just want:

loc = app.EOG()

Then, loc is an instance of EOG, and loc.element_click is a bound method, so it works as intended.