K
from tkinter import *
def fs(event=0):
_geom="200x200+0+0"
if master.geometry().rsplit("+")[0] != _geom.rsplit("+")[0]:
master.geometry(_geom)
master.configure()
elif master.geometry().rsplit("+")[0] == _geom.rsplit("+")[0]:
master.geometry('{0}x{1}+0+0'.format(master.winfo_screenwidth(), master.winfo_screenheight()))
master.configure()
else:
return 0
print(master.geometry())
master=Tk()
master.geometry("200x200+0+0")
b1 = Button(text="FullScreen", command=fs)
b1.pack()
master.bind('<Control-f>', fs)
master.bind('<Control-q>', exit)
master.mainloop()

