Working with Widget after Instance loses the reference

[Al in Dallas]

I made the mistake of creating an instance of a widget and assigning it
to a name I'd already used. Now, if I use root.children or
root.slaves(), I can see the "lost" widget, but can I do anything else
with the string of numbers that shows up when I use root.children? I'd
like to destory the widget, for example. it would be even better if I
could create a new name and have it reference the "lost" widget.

Of course, I can just kill my toplevel and start over.

[John McMonagle]

On Mon, 2006-07-31 at 11:15 -0700, Al in Dallas wrote:

I made the mistake of creating an instance of a widget and assigning it
to a name I'd already used. Now, if I use root.children or
root.slaves(), I can see the "lost" widget, but can I do anything else
with the string of numbers that shows up when I use root.children? I'd
like to destory the widget, for example. it would be even better if I
could create a new name and have it reference the "lost" widget.

Of course, I can just kill my toplevel and start over.

Consider the following code run in the python shell:

>>from Tkinter import *
r = Tk()
b1 = Button(r, text='test')
b1.pack()
b2 = Button(r, text='test2')
b2.pack()
r.children

{'-1210160564': <Tkinter.Button instance at 0xb7de6a4c>, '-1210225748':
<Tkinter.Button instance at 0xb7dd6bac>}

>>r.slaves()

[<Tkinter.Button instance at 0xb7dd6bac>, <Tkinter.Button instance at
0xb7de6a4c>]

>>b1 = 'xxx'
b1.destroy()

Traceback (most recent call last):
File "<stdin>", line 1, in ?
AttributeError: 'str' object has no attribute 'destroy'

>>b1 = r.slaves()[0]
b1.destroy()

So, as long as you know what your widget instance is in root.slaves() or
root.children you can assign it to a new name.


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[Al in Dallas]

John McMonagle wrote:

On Mon, 2006-07-31 at 11:15 -0700, Al in Dallas wrote:

[example of "losing" a widget]

Consider the following code run in the python shell:

>from Tkinter import *
r = Tk()
b1 = Button(r, text='test')
b1.pack()
b2 = Button(r, text='test2')
b2.pack()
r.children

{'-1210160564': <Tkinter.Button instance at 0xb7de6a4c>, '-1210225748':
<Tkinter.Button instance at 0xb7dd6bac>}

>r.slaves()

[<Tkinter.Button instance at 0xb7dd6bac>, <Tkinter.Button instance at
0xb7de6a4c>]

>b1 = 'xxx'
b1.destroy()

Traceback (most recent call last):
File "<stdin>", line 1, in ?
AttributeError: 'str' object has no attribute 'destroy'

>b1 = r.slaves()[0]
b1.destroy()

So, as long as you know what your widget instance is in root.slaves() or
root.children you can assign it to a new name.

Since I've been leaving my shell open, I jumped in and tried:

recoveredlabel = root.slaves()[6]

And after I verified I could manipulate the widget with that
name, I executed:

<original-widget-name= recoveredlabel

Now the only difference between where I was (before I screwed up)
and where I am is that I've got this extra variable named
"recoveredlabel."

Thanks.

Now, do you have any advice on learning the syntax for dealing
with Tix megawidgets in Python? I guess my alternative is to
learn how to use Elmer or SWIG so I can hide all the Python
I've inherited "under the hood" and write my GUI in Tcl/Tk.