超时或用户输入在 Python 循环中重复

Question

在下面的程序中，我是运行在 Windows 7 professional 64 上，我试图让用户在需要时进行干预（通过内部 while 循环）并导致外部 while 循环重复一个动作。否则，内部 while 循环会超时，程序会继续畅通无阻：

import msvcrt
import time

decision = 'do not repeat' # default setting

for f in ['f1', 'f2', 'f3']:

    print ('doing some prepartory actions on f')

    while True: # outer while loop to allow repeating actions on f

        print ('doing some more actions on f')

        t0 = time.time()
        while time.time() - t0 < 10:        # inner while loop to allow user to intervene 
            if msvcrt.kbhit():              # and repeat actions by pressing ENTER if
                if msvcrt.getch() == '\r':  # needed or allow timeout continuation
                    decision = "repeat"
                    break
                else:
                    break
            time.sleep(0.1)

        if decision == "repeat":
            print ("Repeating f in the outer while loop...")
            continue

        else:
            break

    print ('doing final actions on f in the for loop')

但是，内部循环的用户输入部分（按 ENTER 重复）不起作用，我不知道为什么。我从提供的解决方案 here 中得到了它的想法。关于如何让它发挥作用有什么想法吗？

Answer 1

您在内部循环中比较变量决策和字符串 "repeat"，因为您使用的是 == 运算符。您应该使用 = 来为变量赋值：

decision = 'repeat'

Answer 2

我现在已经设法解决了这个问题。 kbhit 进程在我使用的 IDLE 中不起作用（Wing IDE），但如果从命令提示符调用则可以工作（正如@eryksun 所说，这可能适用于所有 IDLE，而不仅仅是翅膀）。我发现的另一个问题是 getch() 进程没有做我需要的，我必须使用 getwch() which returns unicode。再进行一次小调整（默认 decision 和 decision = 'Reset decision to not repeat'，代码现在处于良好的工作状态：

import msvcrt
import time

decision = 'do not repeat' # default setting

for f in ['f1', 'f2', 'f3']:

    print ('doing some prepartory actions on f')

    while True: # outer while loop to allow repeating actions on f

        print ('doing some more actions on f')

        t0 = time.time()
        while time.time() - t0 < 10:        # inner while loop to allow user to intervene 
            if msvcrt.kbhit():              # and repeat actions by pressing ENTER if
                if msvcrt.getchw() == '\r': # needed or allow timeout continuation
                    decision = "repeat"
                    break
                else:
                    break
            time.sleep(0.5)

        if decision == "repeat":
            print ("Repeating f in the outer while loop...")
            decision = 'Reset decision to not repeat'
            continue

        else:
            break

    print ('doing final actions on f in the for loop')

超时或用户输入在 Python 循环中重复

Timeout or User Input to Repeat in Python Loops

python

windows

controls

loops

timeout