Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Python Python Basics All Together Now Handle Exceptions

Deonte Meriwether
Deonte Meriwether
1,513 Points
Posted by Deonte Meriwether
Deonte Meriwether
1,513 Points

Raise value error

My code is looping instead of displaying the value error message. If I enter an invalid respone for number of tickets such as 10000 the code will just loop back and ask for the user name again instead of indicating that the value entered is invalid. Can you show me where I am missing something?

TICKET_PRICE = 10

tickets_remaining = 100

while tickets_remaining >= 1: print("There are {} tickets remaining".format(tickets_remaining)) user_name = input("What is your first name? ") number_of_tickets = input("Hello {}, how many tickets would you like? ".format (user_name)) try: number_of_tickets = int(number_of_tickets) if number_of_tickets > tickets_remaining: raise ValueError ("There are only {} tickets remaining".format (tickets_remaining))

except ValueError as err: print ("oh no that's no a valid value {}. Please try again".format(err))

else: amount_due = TICKET_PRICE * number_of_tickets print ("The total amount due is ${} ".format (amount_due)) should_proceed = input("Do you want to proceed? Y/N ") if should_proceed.lower() == "y": print ("SOLD") #TODO: gather credit card info and process payment
tickets_remaining -= number_of_tickets else: print ("Thank you {}!".format (user_name)) print ("Sorry there are no more tickets available")

1 Answer

KRIS NIKOLAISEN
KRIS NIKOLAISEN
54,972 Points
KRIS NIKOLAISEN
KRIS NIKOLAISEN
54,972 Points

It's hard to tell with how your code is formatted. You should use markdown. I didn't change anything other than possibly indentation and the following appears to work:

TICKET_PRICE = 10

tickets_remaining = 100

while tickets_remaining >= 1:
  print("There are {} tickets remaining".format(tickets_remaining))
  user_name = input("What is your first name? ")
  number_of_tickets = input("Hello {}, how many tickets would you like? ".format(user_name))
  try:
    number_of_tickets = int(number_of_tickets)
    if number_of_tickets > tickets_remaining:
      raise ValueError ("There are only {} tickets remaining".format(tickets_remaining))
  except ValueError as err:
    print ("oh no that's no a valid value {}. Please try again".format(err))

  else:
    amount_due = TICKET_PRICE * number_of_tickets
    print ("The total amount due is ${} ".format (amount_due))
    should_proceed = input("Do you want to proceed? Y/N ")
    if should_proceed.lower() == "y":
      print ("SOLD") #TODO: gather credit card info and process payment
      tickets_remaining -= number_of_tickets
    else:
      print ("Thank you {}!".format (user_name))
print ("Sorry there are no more tickets available")
Deonte Meriwether
Deonte Meriwether
1,513 Points
Deonte Meriwether
Deonte Meriwether
1,513 Points

hmm you know I tried it again and it worked for me also. I think I might have had an extra space in my while statement?? Anyway thank you KRIS for your help! I really appreciate it!