当使用不正确的输入时出现循环值错误

Question

我正在尝试创建一个基本游戏，这个游戏的一个阶段是用户输入1-9的值。如果用户输入其中一个值，游戏就可以运行，但如果他们在到达字段时只点击回车键，我就会得到一个值错误。以下是错误：

<ipython-input-6-061a946b3a03> in <module>
----> 1 ttt_game()
<ipython-input-5-b42c27ce7032> in ttt_game()
36     while game_on == True:
37         while choose_first == 0:
---> 38             player_guess = int(input('Choose a space 1-9: '))
39             for position in board:
40                 if position in board[player_guess] == ' ':
ValueError: invalid literal for int() with base 10: ''

我正试图弄清楚如何再次询问输入调用，或者让while循环重新启动并打印一条消息，比如"；无效输入，请重试"；

如果有帮助的话，这是原始代码块。

while game_on == True:
while choose_first == 0:
player_guess = int(input('Choose a space 1-9: '))
for position in board:
if position in board[player_guess] == ' ':
board[player_guess] = 'X'
display_board(board)
if win_check(board,'x') == False:
pass
else:
display_board(board)
print('Player 1 has won the game!')
break

elif board[player_guess] == 'O':
print ('Space already chosen, choose another.')
pass
else:
choose_first = 1
pass

Answer 1

在将值转换为整数之前，可以将输入封装在while loop周围，以测试该值是否为numeric or digit。

while game_on == True:
while choose_first == 0:
result = ""
while(not result.isdigit()): 
# you can also use result.isnumeric()
result = input('Choose a space 1-9: ')
player_guess = int(result)
for position in board:
if position in board[player_guess] == ' ':
board[player_guess] = 'X'
display_board(board)
if win_check(board, 'x') == False:
pass
else:
display_board(board)
print('Player 1 has won the game!')
break
elif board[player_guess] == 'O':
print('Space already chosen, choose another.')
pass
else:
choose_first = 1
pass