如果它不是介于 0 和 7 之间的整数(包括 0 和 7)，则触发异常

Question

try:
psl = int(input("Source Position - Line Number: "))
psc = int(input("Source Position - Column Number: "))
except ValueError:
print("Error: you have to enter an integer between 0 and 7 inclusivelyn")
continue

在那一小段代码中，玩家必须输入两个介于 0 和 7 之间的整数(包括 0 和 7(，分别对应于一行和一列。我意识到如果我输入9，则永远不会触发异常。如果整数不在 [0， 7] 范围内，如何触发异常？

Answer 1

如果要引发异常，请使用raise关键字。

例如：

try:
psl = int(input("Source Position - Line Number: "))
psc = int(input("Source Position - Column Number: "))
if not (0 <= psl <= 7 and 0 <= psc <= 7):
raise ValueError   # <==== here
self.pss = Pos(psl, psc)
validation = self.validation_ps(self.pss)
except ValueError:
print("Error: you have to enter an integer between 0 and 7 inclusivelyn")
continue

您还可以为其提供关联的错误消息：

raise ValueError("you entered a bad number")

然后要利用它，您需要在except块中的变量(通常为exc(中捕获异常，例如：

except ValueError as exc:
print("the error was ", exc)
# ...

Answer 2

你可以有一个这样的语句：

if not (psl in range(0,8) and psc in range(0,8)):
raise ValueError('Error: you have to enter an integer between 0 and 7 inclusivelyn')

Answer 3

您可以考虑使用断言来处理逻辑，同时保留非数字输入的异常。

try:
psl = int(input("Source Position - Line Number: "))
psc = int(input("Source Position - Column Number: "))
assert (0 <= psl <= 7 and 0 <= psc <= 7), 'Please enter a values between 0 and 7'
except ValueError:
print('Please enter a number!)

Answer 4

是你试图做这样的事情：

while True:
psl = input("Source Position - Line Number: ")
psc = input("Source Position - Column Number: ")
if all([psl.isdigit(), psc.isdigit()]):
if all([7 >= int(psl) >= 0, 7 >= int(psc) >= 0]):
break
print("Error: you have to enter an integer between 0 and 7 inclusivelyn")
self.pss = Pos(psl, psc)
validation = self.validation_ps(self.pss)