如何在Python中检测ESCape按键？

Question

我正在命令窗口（Windows 7，Python
3.1）中运行进程，我希望用户通过按ESCape键来中止该进程。但是，按ESCape键似乎没有执行任何操作:-(，循环永不中断。我也尝试从IDE（机翼）内部运行脚本，但同样，循环也不能中断。

以下是我的概念验证测试的简化版本…

import msvcrt
import time

aborted = False

for time_remaining in range(10,0,-1):
    # First of all, check if ESCape was pressed
    if msvcrt.kbhit() and msvcrt.getch()==chr(27):
        aborted = True
        break

    print(str(time_remaining))       # so I can see loop is working
    time.sleep(1)                    # delay for 1 second
#endfor timing loop

if aborted:
    print("Program was aborted")
else:
    print("Program was not aborted")

time.sleep(5)  # to see result in command window before it disappears!

如果有人能告诉我我可能会出问题的地方，我将不胜感激。

Answer 1

Python 3字符串是unicode，因此必须将其编码为字节以进行比较。试试这个测试：

if msvcrt.kbhit() and msvcrt.getch() == chr(27).encode():
    aborted = True
    break

还是这个测试：

if msvcrt.kbhit() and msvcrt.getch().decode() == chr(27):
    aborted = True
    break

还是这个测试：

if msvcrt.kbhit() and ord(msvcrt.getch()) == 27:
    aborted = True
    break