如何在不使用KeyboardInterrupt的情况下从按键退出while循环？[蟒蛇]

这是我向你保证的例子。

我不需要为此程序导入任何mod，但是我相信用来控制键盘输入的msvcrt mod是Windows特定的。是因为它可能; 即使我们使用不同的方法来控制键盘输入，但我希望您能看到在主程序重复循环并处理键盘输入时如何通过按键来控制秒表。

import time     # Contains the time.time() method.
import winsound # Handle sounds.
import msvcrt   # Has Terminal Window Input methods 
# ===========================================
# -------------------------------------------
# --              Kbfunc()                 --
# Returns ascii values for those keys that
# have values, or zero if not.
def kbfunc():
    return ord(msvcrt.getch()) if msvcrt.kbhit() else 0
# -------------------------------------------
# --           Get_Duration()              --
# Gets the time duration for the stopwatch.
def get_duration():
    value = input("\n How long do you want the timer to run? ")
    try:
        value = float(value)
    except:
        print("\n\t** Fatal Error: **\n Float or Integer Value Expected.\n")
        exit()
    return value
# ===========================================
#                   Body    
# ===========================================
# To keep the program as simple as possible, we will only use
# standard ascii characters. All special keys and non-printable
# keys will be ignored. The one exception will be the
# carriage return key, chr(13).
# Because we are not trapping special keys such as the
# function keys, many will produce output that looks like
# standard ascii characters. (The [F1] key, for example,
# shares a base character code with the simicolon.)

valid_keys = [] # Declare our valid key list.
for char in range(32,127):  # Create a list of acceptable characters that
    valid_keys.append(char) # the user can type on the keyboard.
valid_keys.append(13)       # Include the carriage return.

# ------------------------------------------
duration = 0
duration = get_duration()

print("="*60)
print(" Stopwatch will beep every",duration,"seconds.")
print(" Press [!] to turn Stopwatch OFF.")
print(" Press [,] to turn Stopwatch ON.")
print(" Press [@] to quit program.")
print("="*60)
print("\n Type Something:")
print("\n >> ",end="",flush = True)

run_cycle = True # Run the program until user says quit.
stopwatch = True # Turn the stopwatch ON.
T0 = time.time() # Get the time the stopwatch started running.

while run_cycle == True:
    # ------
    if stopwatch == True and time.time()-T0 > duration: # When the duration
        winsound.Beep(700,300)  # is over, sound the beep and then
        T0 = time.time()          # reset the timer.
    # -----
    key = kbfunc()
    if key == 0:continue # If no key was pressed, go back to start of loop.    
    
    if key in valid_keys: # If the user's key press is in our list..
        
        if key == ord(","): # A comma means to restart the timer.
            duration = get_duration()         # Comment line to use old duration.
            print(" >> ",end="",flush = True) # Comment line to use old duration.
            t0 = time.time()
            stopwatch = True
            continue # Remove if you want the ',' char to be printed.
        
        elif key == ord("!"): # An exclamation mark means to stop the timer.")
            stopwatch = False
            continue # Remove if you want the "!" to print.
        
        elif key == ord("@"):  # An At sign means to quit the program.
             print("\n\n Program Ended at User's Request.\n ",end="")
             run_cycle = False # This will cause our main loop to exit.
             continue # Loop back to beginning so that the at sign
                      # is not printed after user said to quit.
             
        elif key == 13: # The carriage return means to drop down to a new line.
            print("\n >> ",end="",flush = True)
            continue
             
        print(chr(key),end="",flush = True) # Print the (valid) character. 
        # Keys that are not in our list are simply ignored.