Threading and tkinter

[gert]

On Feb 18, 8:25 am, "Hendrik van Rooyen" <m... at microcorp.co.za> wrote:
> "gert" <gert.cuyk... at gmail.com>wrote:
>
> > After reading the docs and seeing a few examples i think this should
> > work ?
> > Am I forgetting something here or am I doing something stupid ?
> > Anyway I see my yellow screen, that has to count for something :)
>
> > from tkinter import *
> > from threading import Thread
>
> > class Weegbrug(Thread):
> >     def __init__(self,v):
> >         self.v=v
> >         Thread.__init__(self)
> >     def run(self):
> >         while True:
> >             with open('com1','r') as f:
> >                  for line in f:
> >                      self.v.set(line[2:-1])
>
> It is in general not a good idea to directly
> access GUI variables from outside the
> GUI main loop.
> There is a recipe for doing this sort of thing,
> but as usual I have lost the reference.
> What it does is that instead of interfering directly
> as above, you put the data on a queue.
>
> Then, you use the after() call to set up a call
> to a routine that reads the queue, and configures the
> display, and then uses after again to call itself again
> after a time, thereby keeping the GUI stuff in the GUI
> mainloop.
>

from tkinter import *
from threading import Thread

class Weegbrug(Thread):
    def __init__(self):
        self.display='00000'
        Thread.__init__(self)
    def run(self):
        x=0
        while True:
            x=x+1
            self.display=x
            #with open('com1','r') as f:
            #     for l in f:
            #         self.display=l[2:-1]

root = Tk()
v = StringVar()
v.set('00000')
w = Weegbrug()
w.start()
tx = Label(root, textvariable=v, width=800, height=600, bg='yellow',
font=('Helvetica', 300))
tx.pack(expand=YES, fill=BOTH)
root.title('Weegbrug')
root.overrideredirect(1)
root.geometry('%dx%d+0+0' % (root.winfo_screenwidth(),
root.winfo_screenheight()))
root.after(500, v.set(w.display))
root.mainloop()

Why does this not work ?
It only shows one result ?