TKinter: No response when capturing key presses

Lots of issues in your code -

1. Your binding seems to be wrong -

   self.bind(self, "<space>", pressSpace)

   Not sure why you are sending self again. You should be doing -

   self.bind("<space>", pressSpace)

2. In your function - pressSpace() - since you are setting paused=0 or paused=1 , the paused is treated as local variable to that function, so you would get an error - UnboundLocalError: local variable 'paused' referenced before assignment . Instead , I would adivce you to set paused as an instance variable on self and use it.

3. Secondly, even if binding becomes correct, in each call to countdown , you are changing paused back to 0. For this you should move the binding and setting paused to 0 logic to __init__() . and then when the application is unpaused you would need to re-start the countdown.

Code that works -

import Tkinter as tkclass ExampleApp(tk.Tk):    def __init__(self):        tk.Tk.__init__(self)        # make program fullscreen        w, h = self.winfo_screenwidth(), self.winfo_screenheight()        self.geometry("%dx%d+0+0" % (w, h))        self.label = tk.Label(self)        self.label.pack()        self.remaining = 0        self.paused = 0        def pressSpace(event):            if(self.paused == 0):                self.paused = 1            else:                self.paused = 0                self.countdown()        #bind spacebar to pause the timer        self.bind("<space>", pressSpace)        self.countdown(15)    def countdown(self, remaining = None):        if remaining is not None:            self.remaining = remaining        if self.remaining <= 0:            #Time has expired. Players lose            self.label.configure(text="TIME!", fg='black', bg='brown')        else:            #There is still time on the clock. This cuts the time into readable chunks            self.label.configure(text= str(self.remaining) + ' - Paused = ' + str(self.paused))            if(self.paused == 0):                #Check if the timer is toggled to pause                self.remaining = self.remaining - 1                self.after(1000, self.countdown)if __name__ == "__main__":    app = ExampleApp()    app.mainloop()