未捕获 ValueError

Question

我在捕获 ValueError 异常时遇到了一些问题。

如果我用字符串测试输入，即 'a' 而不是提供 int 数字，那么它会按预期抛出 ValueError。但是为什么我的异常没有捕获这个并打印“错误，用整数再试一次”？

我给了它 've' 因为我还没有用过这个变量。我没有给出 'e'，因为我已经将其用于另一个例外。

如果我改为尝试 except (TypeError,ValueError): 那么为什么这也不起作用？

注意，这段代码只是让我练习处理异常，内容本身没有意义。

while not correct_input:
    distance_travelled = float(input("enter distance travelled in km: ")) #input enters strings, so you must convert to the datatype you want
    monetary_value = float(input("amount paid to cover distance: "))
    price_per_litre = 1.59
    try:
        fuel_consumed = monetary_value/price_per_litre
        if monetary_value/price_per_litre < 0:
            raise Exception #I can raise my own custom exception here
    except Exception as e:
        print("too small, try again")
    except ValueError as ve: #Catch our exception, and handle it properly. Ensure specific exceptions at the top, general at the bottom
        print("error, try again with an integer")
    else: #Runs code if try doesn't raise an exception
        print(fuel_consumed)
        correct_input = True
    finally: #Regardless of error or not, what you wish for it to do. i.e. close a file, close database etc
        continue

谢谢

Answer 1

< 0 只有当您输入负值时，您才会满足此条件，请查看您是否需要或 < 1。否则代码如下。

correct_input = False
while not correct_input:
    try: # just check if you are getting integer/floating value here only
        distance_travelled = float(input("enter distance travelled in km: ")) #input enters strings, so you must convert to the datatype you want
        monetary_value = float(input("amount paid to cover distance: "))
    except:
        print('Only Integer and Floting point number')
    price_per_litre = 1.59
    try:
        fuel_consumed = monetary_value/price_per_litre
        if monetary_value/price_per_litre < 0: # I have a doubt if you really want 0 here. OR 1
            raise ValueError # raise value error when condition is met.
    except ValueError as ve:
        print('Too Small')

    else:
        print(fuel_consumed)
        correct_input = True
    finally:
        continue

未捕获 ValueError

ValueError not being caught

python

exception

valueerror