按 ENTER 退出程序 Python 不工作

Question

试图让我的代码在按下回车按钮时退出，我运行进入 ValueError: invalid literal for int() with base 10: ''，但它告诉我我的错误在 [=13] 行=].有人有想法吗？

simulations = input("How many times would you like to run the simulation? ")

# Invalid answer, system exit
if (not simulations) or int(simulations) <=0:    
   print("That is not a valid number of simulations.")
   print("Shutting down.")
   SystemExit

simulations_num = int(simulations)
#the rest of my code comes here

我也尝试过 if simulations == '' 但无济于事。我注意到如果 simulations_num = int(simulations) 不涉及，代码工作正常，但代码的其余部分（或类似的东西）是必要的

Answer 1

您需要 raise SystemExit()，或者只使用 sys.exit()（做同样的事情）。

Answer 2

您需要提出错误，或者至少使用 sys.exit(0)。工作原理是这样的：

import sys
if not input(': ').lower() in ['yes','y','1']:
    sys.exit(0)

应用于你的例子就是这个

simulations = input("How many times would you like to run the simulation? ")

import sys

# Invalid answer, system exit
if (not simulations) or int(simulations) <=0:    
   print("That is not a valid number of simulations.")
   print("Shutting down.")
   sys.exit(0)

simulations_num = int(simulations)
#the rest of my code comes here

raise RuntimeError()也可以

Answer 3

解决您的代码：

首先，您需要在SystemExit的前面加上“raise”关键字，它才能正常工作。其次，要建立一个必须按Enter键才能让程序退出的情况，可以使用input()。

更正版本：

simulations = input("How many times would you like to run the simulation? ")

# Invalid answer, system exit
if (not simulations) or int(simulations) <= 0:
    print("That is not a valid number of simulations.")
    print("Shutting down.")
    input("Press Enter to exit...")
    raise SystemExit("Exiting... Reason: invalid input!")

simulations_num = int(simulations)
# the rest of my code comes here

按 ENTER 退出程序 Python 不工作

Press ENTER to exit program in Python not working

python

exit-code