在python中检测按键，其中每次迭代可能需要超过几秒钟的时间？

Question

编辑：下面使用keyboard.on_press（回调，suppress=False）的答案在ubuntu中工作正常，没有任何问题。但是在Redhat/Amazon linux中，它无法正常工作。我使用了此线程中的代码片段import keyboard  # using module keyboardwhile True:  # making a loop    try:  # used try so that if user pressed other than the given key error will not be shown        if keyboard.is_pressed('q'):  # if key 'q' is pressed             print('You Pressed A Key!')            break  # finishing the loop    except:        break  # if user pressed a key other than the given key the loop will break但上面的代码要求每次迭代都要在纳秒内执行。在以下情况下会失败：import keyboard  # using module keyboardimport timewhile True:  # making a loop    try:  # used try so that if user pressed other than the given key error will not be shown        print("sleeping")        time.sleep(5)        print("slept")        if keyboard.is_pressed('q'):  # if key 'q' is pressed             print('You Pressed A Key!')            break  # finishing the loop    except:        print("#######")        break  # if user pressed a key other than the given key the loop will break

Answer 1

您可以使用模块中的事件处理程序来实现所需的结果。keyboard

一个这样的处理程序是keyboard.on_press（回调，suppress=False）：它为每个事件调用一个回调。您可以在键盘文档中了解更多信息key_down

以下是您可以尝试的代码：

import keyboard  # using module keyboard

import time

stop = False

def onkeypress(event):

    global stop

    if event.name == 'q':

        stop = True

# ---------> hook event handler

keyboard.on_press(onkeypress)

# --------->

while True:  # making a loop

    try:  # used try so that if user pressed other than the given key error will not be shown

        print("sleeping")

        time.sleep(5)

        print("slept")

        if stop:  # if key 'q' is pressed 

            print('You Pressed A Key!')

            break  # finishing the loop

    except:

        print("#######")

        break  # if user pressed a key other than the given key the loop will break

Answer 2

对于将来可能需要它的人，您可以使用它基本上等到按键被按下keyboard.wait()

keyboard.wait("o")

print("you pressed the letter o")

请记住，它会阻止代码执行。如果你想运行代码，如果键没有被按下，我建议做

if keyboard.is_pressed("0"): 

    #do stuff

else: 

    #do other stuff

Answer 3

没关系，另一个答案使用几乎相同的方法

这是我可以想到的，使用相同的“键盘”模块，请参阅下面的代码内注释

import keyboard, time

from queue import Queue 

# keyboard keypress callback

def on_keypress(e): 

    keys_queue.put(e.name)

# tell keyboard module to tell us about keypresses via callback

# this callback happens on a separate thread

keys_queue = Queue() 

keyboard.on_press(on_keypress)

try:

    # run the main loop until some key is in the queue

    while keys_queue.empty():  

        print("sleeping")

        time.sleep(5)

        print("slept")

    # check if its the right key

    if keys_queue.get()!='q':

        raise Exception("terminated by bad key")

    # still here? good, this means we've been stoped by the right key

    print("terminated by correct key")

except:

    # well, you can 

    print("#######")

finally:

    # stop receiving the callback at this point

    keyboard.unhook_all()

Answer 4

您可以使用线程

import threading

class KeyboardEvent(threading.Thread):

    def run(self):

        if keyboard.is_pressed('q'):  # if key 'q' is pressed 

            print('You Pressed A Key!')

            break  # finishing the loop

keyread = KeyboardEvent()

keyread.start()

这将与主线程中的任何内容并行运行，并且专门用于基本上侦听该按键。