Press esc to stop and any other key to continue in Python

Question

Now with help of raw_input, I can call a method every time user presses Enter.

if __name__ == '__main__':
    while True:
        raw_input("Press Enter to continue...")
        _start()
def _start():
     print("HelloWorld")

There is a problem because only Ctrl + C, the program can be stopped. As you see, I make my program to wait user to press key.

From opencv, I find there is a similar need.

# Hit 'q' on the keyboard to quit!
if cv2.waitKey(1) & 0xFF == ord('q'):
    break

Simply I want to press esc key to exit program and press any other key to continue. So there is any way to do like this?

In Addition

My os is OSX.

Solution

you can use pynput,it's easier to use.

from pynput import keyboard

def _start():
     print("HelloWorld")
def on_press(key):
    if key == keyboard.Key.esc:
        # Stop listener
        return False
    else:
        _start()

# Collect events until released
with keyboard.Listener(
        on_press=on_press) as listener:
    listener.join()

Comments

[CoXier]

The output is very strange.

[ChatterOne]

Can you be a bit more specific? There should be no output except for the keys that you press

[CoXier]

Yes after I press ESC, the output disappear. But when the program is running, I press any other key, the format of output is very strange.

[ChatterOne]

I tried this on OS X and iTerm2, are you using a different terminal?

[CoXier]

Have you added _start() method?

[ChatterOne]

If you are in a curses screen, print might work slightly differently. If you're talking about the fact that it doesn't go back to the start of the line, try adding a \r to the end of the string, like print('HelloWorld\r') and see if that works.

[CoXier]

From doc pynput.readthedocs.io/en/latest/limitations.html#mac-osx, I find we must run program as root.