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 (Retired) Putting the "Fun" Back in "Function" Shopping List Redux

Posted by Leila Loezer
Leila Loezer
4,869 Points

Empty shopping list items

When this code is running, if I press "enter" without inputting any text the code still adds an item to the list, so I have an empty or null item. What would be the best way to prevent creating these empty items? This is the part of the code for the new_item input:

while True: new_item = input("> ")

1 Answer

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,441 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,441 Points

One way to reject empty input would be to check if input is the empty string then continue the loop for the next input:

while True:
    new_item = input("> ")
    if new_item == "":
        continue

    # remain input processing code here
Kenneth Love
Kenneth Love
Treehouse Guest Teacher
Kenneth Love
Kenneth Love
Treehouse Guest Teacher 
if new_item:

should be sufficient. An empty string is false-y.