In my CS class, my students just finished their first "clone your classic" contest. The PONG team went rapidly through the "Hey my paddle is frozen" issue with their two players on one keyboard version. I came across this problem 5 years ago and found Python bind - allow multiple keys to be pressed simultaniously that enlightened me (watch out ! The article uses python2.7). But I didn't realize then that the script only worked on windows machines.
On a linux system, the <KeyRelease-a> event triggers the callback, but the event.char then points to ' ' and not 'a' as one could expect. I tried googling the issue, but even on stackoverflow I couldn't find anything of interest.
Any hints? Next find the reproducible code sample:
import os
from tkinter import *
os.system("xset r off")
def keyup(e):
#print(f"up {e.char}")
print(f"up {e.keysym}")
def keydown(e):
#print(f"down {e.char}")
print(f"down {e.keysym}")
root = Tk()
frame = Frame(root, width=100, height=100)
frame.bind("<KeyPress>", keydown)
frame.bind("<KeyRelease>", keyup)
frame.pack()
frame.focus_set()
root.mainloop()
os.system("xset r on")
for reproducibility as asked by Bryan, which I thank for his concern about my question.
Just to close the subject, all the job has been done by Atlas435 : if you want to code a Pong with Tkinter, with two paddles listening independently to the keystrokes, follow this post Python bind - allow multiple keys to be pressed simultaniously but change e.char into e.keysym in the callbacks to get which key triggered the event Pressed or Released.