Mailing List Archive: Tkinter: some Labels not updating

Hi,

I'm writing a small app using Python and Tkinter and I'm having trouble
with some Label objects not updating when I set the StringVar object
attached to the textvariable of the Label.

My Tkinter window has a Canvas with a bitmap image in one Frame,
pull down menus in another Frame, and a few Buttons and Labels. The
Labels are supposed to indicate the values of certain variables which
change when the user clicks on the canvas. The first Label changes,
but the others don't, they stay fixed at the values they had when
I created the Label.

Is there a trick here or something I don't get?

I first create the StringVar:

self.X1v=StringVar()

Then I initialize X1v:

self.X1v.set("X1: not entered")

Then I make a Label object

self.l1=Label(tb, textvariable=self.X1v)
self.l1.pack(side=TOP)

Then in the mouse callback (yes, it gets run, I have it print to stdout)

self.X1v.set("X1: Got It")

But no update of the text in the label happens. Updates _do_ happen
in another Label object that is in a Frame by itself. Do I need a
separate Frame for each Label? Do I have too many Label objects?
Any workarounds? Post or e-mail replys.

Thanks,

JDM -- python enthusiast whose reach exceeds his grasp. :)

python@pinky.cchem.berkeley.edu wrote:
> My Tkinter window has a Canvas with a bitmap image in one Frame,
> pull down menus in another Frame, and a few Buttons and Labels. The
> Labels are supposed to indicate the values of certain variables which
> change when the user clicks on the canvas. The first Label changes,
> but the others don't, they stay fixed at the values they had when
> I created the Label.
>
> Is there a trick here or something I don't get?
>
> I first create the StringVar:
>
> self.X1v=StringVar()
>
> Then I initialize X1v:
>
> self.X1v.set("X1: not entered")
>
> Then I make a Label object
>
> self.l1=Label(tb, textvariable=self.X1v)
> self.l1.pack(side=TOP)
>
> Then in the mouse callback (yes, it gets run, I have it print to stdout)
>
> self.X1v.set("X1: Got It")
>
> But no update of the text in the label happens. Updates _do_ happen
> in another Label object that is in a Frame by itself. Do I need a
> separate Frame for each Label? Do I have too many Label objects?

as far as I can tell, your program should work. which means that
there's probably something you forgot to tell us. try to make a
small but complete program that illustrates the problem.

(btw, if nothing else helps, you could skip the textvariables and
use self.l1.config(text="X1: Got it") instead...)

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