[wxPython-users] Help with GetApp()

[Christopher Barker]

Rob McMullen wrote:
>> Can someone please explain to me why this does not work and suggest a way of
>> accomplishing my objective.
> 
> It's because you use print_const in the constructor of your MainFrame,
> and python hasn't completed building the class.  Until the constructor
> returns, the reference to the MainFrame isn't valid in your app.

Also note that you are putting CONSTANT in your frame class -- does it 
belong there, or should it be an attribute of the app itself. The way 
you have it violates the "law of Demeter" -- now anything working with 
the app needs to know that it has a "frame" attribute, and that the 
frame attribute as a "CONSTANT" attribute -- no too bad, but starting to 
get too deep.

Also, I know this is probably a simplified sample, but:

class MainFrame(wx.Frame):
     CONSTANT = 3
     def __init__(self, *args, **kwargs):
         wx.Frame.__init__(self, *args, **kwargs)
	print_const()

Why would you want to call a global function to print an attribute of 
your frame class, from that class?

In general, I avoid global functions altogether -- why not have 
print_const() be a method of your app?

-Chris

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Christopher Barker, Ph.D.
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