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Python Python Basics All Together Now Handle Exceptions

Posted by Allen Hoessli
Allen Hoessli
496 Points

Negative entry

I was testing this code. Instead of going to 10000 to catch a ValueError, I typed -10. When I completed the transaction, it added 10 to the total. In a real life situation, we probably wouldn't want that problem. How could we remedy that?

Nicolás Melgarejo
Nicolás Melgarejo
15,532 Points
Nicolás Melgarejo
Nicolás Melgarejo
15,532 Points

I use this:

number_of_tickets = input("How many tickets do you like {}?   ".format(user_name))
    # Expect a ValueError
    try:
        number_of_tickets = int(number_of_tickets)
        if number_of_tickets > tickets_remaining:
            raise ValueError("The number of tickets that you want to buy exeed de number of tickets remaining ({}).".format(tickets_remaining))
        elif number_of_tickets <= 0:
            raise ValueError("More than 0 tickets are require.")
    except ValueError as err:
        print("Oh no, we ran into a issue. Please try again")
        print("{}".format(err))

1 Answer

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

The easiest solution might be to have another test, such as if num_tickets <= 0. If that condition is true, you could raise a ValueError with a message like "your entry must be a positive number".