global_hotkeys.py

import win32api, win32con
import time
import threading

import sys

def is_pressed(key):
    x = win32api.GetKeyState(key)
    return (x & (1 << 8)) != 0
    
#executes `callback` whenever the key state changes from off to on.
#terminates when the user presses the Q button.
def key_detection_thread(key, callback):
    keys = {key: "pressed", ord("Q"): "quit"}
    prev_states = {key: False for key in keys.iterkeys()}
    while True:
        for key, msg in keys.iteritems():
            prev_state = prev_states[key]
            cur_state = is_pressed(key)
            if cur_state and not prev_state:
                if msg == "quit": return
                if msg == "pressed": callback()
            prev_states[key] = cur_state
        time.sleep(0.01)

#spawn `key_detection_thread` asynchronously so the while loop doesn't block the rest of your program forever.
def listen(key, callback):
    t = threading.Thread(target=key_detection_thread, args=(key, callback))
    t.daemon = True
    t.start()