处理倒数计时器的空输入：以 10 为底的 int() 的无效文字：''

Question

我刚开始 Python 并试图制作一个倒数计时器并尽可能使其牢不可破，但是当我输入空白时，while 循环无法处理它，并且显示此消息将改为显示：以 10 为底的 int() 的无效文字：''。它还指出了在要求倒计时的那一行发生的错误。

我们将不胜感激。

while countdown == 0 or countdown == "": 
      print("We need a person to countdown.") 
      countdown = int(input("How many seconds would you like the countdown to be?: ")) 
  while countdown > 30: 
      try: 
          countdown = int(input("Enter non-extreme values please: ")) 
      except ValueError: 
          print("Enter possible value.") 
  while countdown > 0: #Countdown sequence
      time.sleep(2) 
      countdown -= 1 
      print(countdown) 
  print("BLASTTT OFFFFFFFFFFFFFF!!!") 
  print("We have a liftoff...")

Answer 1

无法转换为 int 的错误字符串将引发 ValueError。您捕捉到该异常并像这样重复提示：

countdown = 0
while countdown <= 0:
    try:
        countdown = int(input("How many seconds would you like the countdown to be?: "))
    except ValueError:
        pass

一旦输入大于 0 的正确整数，while 就会中断。

处理倒数计时器的空输入：以 10 为底的 int() 的无效文字：''

Handling null inputs for countdown timer: invalid literal for int() with base 10: ''

python

input

while-loop

countdown