如何在python中通过键盘按下停止秒表？

Question

我在 python 中制作了一个超级基本的秒表，只是为了让自己更适应它，（这是我的第一种编程语言）并且我一直试图让代码在按下键时停止运行（使用键盘中断) 但代码基本上忽略了键盘中断并一直持续下去。 （这是我的代码供参考）

# Time
import time
import sys
timeLoop = True
# Variables to keep track and display
Sec = 0
Min = 0
Hour = 0
# Begin Process
timeloop = True
while timeloop == True:
    try:
        Sec += 1
        print(str(Hour) + " Hrs " + str(Min) + " Mins " + str(Sec) + " Sec ")
        time.sleep(1)
        if Sec == 60:
            Sec = 0
            Min += 1
            print(str(Min) + " Minute")
            if Min == 60:       
                Sec = 0
                Min = 0 
                Hour += 1
                print(str(Hour) + " Hours")
    except KeyboardInterrupt:
        sys.exit(0)

Answer 1

使用第二个线程（https://en.wikipedia.org/wiki/Multithreading_(computer_architecture)、How to use threading in Python?）：

def quit_on_user_input():
    input = raw_input("Press any key to quit.")
    # thread will lock up and wait for user to input. That's why this is on a separate thread.
    sys.exit(0)

quit_thread = threading.Thread(target=quit_on_user_input, args=[])
quit_trhead.start()
# The rest of your code. quit_thread will run in the background and therefor won't lock up your main thread.

Answer 2

当用户使用ctrl + c 退出程序时，会抛出KeyboardInterrupt 异常。您将需要使用另一种方法来检测按键。 This answer 似乎有一个很好的跨平台类来检查标准输入。

编辑：我上面链接的答案需要用户按回车键，这样如果你在不同的线程中运行它就可以工作。

以下方法适用于任何按键，但仅适用于 Windows。

import msvcrt
# Time
import time
import sys
timeLoop = True
# Variables to keep track and display
Sec = 0
Min = 0
Hour = 0
# Begin Process
while True:
    try:
        Sec += 1
        print(str(Hour) + " Hrs " + str(Min) + " Mins " + str(Sec) + " Sec ")
        time.sleep(1)
        if Sec == 60:
            Sec = 0
            Min += 1
            print(str(Min) + " Minute")
            if Min == 60:
                Sec = 0
                Min = 0
                Hour += 1
                print(str(Hour) + " Hours")
        if msvcrt.kbhit():
            break
    except KeyboardInterrupt:
        break

EDIT2：Found a library for kbhit that has cross-platform support。在下面的示例中，我将其保存在与 kbhit.py 相同的目录中，并在第 1 行导入。

from kbhit import KBHit
# Time
import time
import sys
timeLoop = True
# Variables to keep track and display
Sec = 0
Min = 0
Hour = 0

k = KBHit()
# Begin Process
while True:
    try:
        Sec += 1
        print(str(Hour) + " Hrs " + str(Min) + " Mins " + str(Sec) + " Sec ")
        time.sleep(1)
        if Sec == 60:
            Sec = 0
            Min += 1
            print(str(Min) + " Minute")
            if Min == 60:
                Sec = 0
                Min = 0
                Hour += 1
                print(str(Hour) + " Hours")
        if k.kbhit():
            break
    except KeyboardInterrupt:
        break