TkInter displays extra windows after winfo is called.

[Gregory Sherrod]

#! /usr/bin/python
# This one creates three windows because of the Tk().winfo_screenwidth(),
# Tk().winfo_screenheight() call
 
from Tkinter import *
 
def quit(): sys.exit(0)
 
root = Tk()
root.title("Test screen")
w, h = Tk().winfo_screenwidth(), Tk().winfo_screenheight()
h = h * 0.75
paper = Canvas(root, width = h, height = h, bg = "#000020")
 
a = h / 10
b = h - a
 
paper.create_line(a, a, b, b, fill="white")
paper.create_line(a, b, b, a, fill="white")
 
exitB = Button(text="Exit", width=15, command=quit)
exitB.pack()
 
paper.pack()
mainloop()
 

#! /usr/bin/python
# This one creates only a single window.
 
from Tkinter import *
 
def quit(): sys.exit(0)
 
root = Tk()
root.title("Test screen")
 
h = 400
paper = Canvas(root, width = h, height = h, bg = "#000020")
 
a = h / 10
b = h - a
 
paper.create_line(a, a, b, b, fill="white")
paper.create_line(a, b, b, a, fill="white")
 
exitB = Button(text="Exit", width=15, command=quit)
exitB.pack()
 
paper.pack()
mainloop()
 

Any idea how to easily fix this? Thanks in advance...

Greg

[dwblas]

You are starting 3 instances of Tk(). Use root instead

##--- instance 1
root = Tk()
root.title("Test screen")
 
##-- instances 2 & 3
w, h = Tk().winfo_screenwidth(), Tk().winfo_screenheight()
 
""" this opens one window only
""
root = Tk()
root.title("Test screen")
w, h = root.winfo_screenwidth(), root.winfo_screenheight() 

Also, to exit, use the quit command instead of sys.exit.

exitB = Button(text="Exit", width=15, command=root.quit)

[Gregory Sherrod]

Like most errors, this one is trivial when solved, but opaque beforehand. Many thanks, dwblas!

[bvdet]

Gregory,

Since you have gotten your answer, please mark the appropriate post with the 'choose as best answer button'. This makes it easier for the next person to find the solution.