Raising Exceptions...

Question

TICKET_PRICE = 10
def pricecalculator(TICKETPRICE, numberoftickets):
    if numberoftickets <= 0:
        raise ValueError("Tickets ordered have to be more that 0. Please try again.")
    elif numberoftickets > ticketsremaining: 
        raise ValueError("Sorry {}, there are only {} tickets remaining. Please try again.".format(name, ticketsremaining))
    return TICKETPRICE * numberof_tickets
ticketsremaining = 100
while ticketsremaining > 0:
    name = input("Hi, What is your name?  ")
    print("Hi {}, there are {} tickets remaining.".format(name, ticketsremaining))
    try:
        numberoftickets = int(input("How many tickets would you like {}?  ".format(name)))
        cost = pricecalculator(TICKETPRICE, numberoftickets)
    except ValueError as err:
        print("Oh no, we ran into an issue. Please try again.")
        print("{}".format(err))
    else:
        print("The total due is ${}.".format(cost))
        decision = input("Would you like to proceed with the purchase?
(Enter Y/N)")
        if decision.lower() == "y":
            print("SOLD!! Enjoy the show {}.".format(name))
            ticketsremaining -= numberoftickets
        else:
            print("Thank you for your time {}.".format(name))
print("Sorry, all the tickets are sold out!😭")
I opted to use a function for this command line application. I thought I handled all the exceptions but whenever a user enters a string for the 'numberoftickets_variable' I keep getting this error in the console: "invalid literal for int() with base 10: 't'". Is there any change I can make to this code to handle the error in a user-friendly manner?

Steven Parker · Answer

That's the correct system error message, though as you point out it's not terribly "user friendly".  But you can show anything you like:
```python
print("{}".format(err))                          # so instead of the system error
print("Be sure to enter a number this time!")    # you could show something else
```

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Alan Aranga

Alan Aranga

Raising Exceptions...

Alan Aranga

Alan Aranga

Steven Parker

Steven Parker

1 Answer

Steven Parker

Steven Parker