如何用Python的pynput实现函数重复执行直至按下指定按键？

Got it, let's get this working for you! Since the keyboard library isn't playing nice on your macOS Mojave setup, pynput is a reliable alternative that should handle key detection perfectly. Here's a step-by-step implementation that matches your desired logic:

Step 1: Install pynput #

First, make sure you have the library installed (if you haven't already):

pip install pynput

Step 2: Full Implementation Code #

This code will run your function() in a loop and exit as soon as you press the q key:

from pynput.keyboard import Listener
import time

# Flag to track if we need to stop the loop
stop_loop = False

def function():
    # Replace this with your actual function logic
    print("Executing your function...")
    time.sleep(0.5)  # Simulate work - remove this in your real code

def check_for_q(key):
    global stop_loop
    try:
        # Trigger stop when 'q' is pressed
        if key.char == 'q':
            stop_loop = True
            return False  # Stop the listener thread
    except AttributeError:
        # Ignore special keys like Shift/Ctrl - we only care about 'q'
        pass

if __name__ == "__main__":
    # Start the key listener in a background thread
    listener = Listener(on_press=check_for_q)
    listener.start()

    # Run your function on loop until 'q' is pressed
    while not stop_loop:
        function()

    # Clean up the listener
    listener.join()
    print("Loop exited successfully after pressing 'q'!")

Key Notes for macOS #

• Permissions: When you run this script for the first time, macOS will prompt you to grant input monitoring access to Python. Go to System Preferences > Security & Privacy > Privacy > Input Monitoring and check the box next to your Python interpreter to allow this. Without this permission, pynput can't detect key presses.
• Non-blocking: The key listener runs in a separate thread, so your function() will keep running smoothly without being interrupted by key checks.

Alternative: Cleaner Approach Without Global Variables #

If you want to avoid global variables (a better practice for larger scripts), you can use a class to encapsulate the state:

from pynput.keyboard import Listener
import time

class LoopController:
    def __init__(self):
        self.stop_loop = False

    def function(self):
        print("Executing your function...")
        time.sleep(0.5)

    def check_for_q(self, key):
        try:
            if key.char == 'q':
                self.stop_loop = True
                return False
        except AttributeError:
            pass

    def run(self):
        listener = Listener(on_press=self.check_for_q)
        listener.start()

        while not self.stop_loop:
            self.function()

        listener.join()
        print("Loop exited!")

if __name__ == "__main__":
    controller = LoopController()
    controller.run()

This works exactly the same way but keeps your state organized in a class instead of using globals.

内容的提问来源于stack exchange，提问作者Raz P