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 Introducing Lists Build an Application Multidimensional Musical Groups

nick schubert
nick schubert
3,535 Points
Posted by nick schubert
nick schubert
3,535 Points

I don't know what I'm doing wrong here.

In this challenge I have to show Trio's only.

When I run this code in workspaces it works just fine, but when I press "Check Work" I receive an AssertionError saying that it's detecting non-trio's. I have been trying to debug this for quite a while now and I can't figure out what I'm doing wrong, so, all help is appreciated!

groups.py 
musical_groups = [
    ["Ad Rock", "MCA", "Mike D."],
    ["John Lennon", "Paul McCartney", "Ringo Starr", "George Harrison"],
    ["Salt", "Peppa", "Spinderella"],
    ["Rivers Cuomo", "Patrick Wilson", "Brian Bell", "Scott Shriner"],
    ["Chuck D.", "Flavor Flav", "Professor Griff", "Khari Winn", "DJ Lord"],
    ["Axl Rose", "Slash", "Duff McKagan", "Steven Adler"],
    ["Run", "DMC", "Jam Master Jay"],
]
# Your code here
for member in musical_groups:
    members = ", ".join(member)
    print(members)
    if len(member) == 3:
        trio = ", ".join(member)
        print(trio)

1 Answer

Steven Parker
Steven Parker
229,644 Points
Steven Parker
Steven Parker
229,644 Points

You'll want to "print" only after making the length test. As it is, every group is printed at least once, and trios are printed twice.

Also, you don't need to create that separate "members" variable, since you'll only be printing "trio".

nick schubert
nick schubert
3,535 Points
nick schubert
nick schubert
3,535 Points

Ah I got it, I passed the challenge when I removed the print(members) line.

Thanks for the quick reply! I appreciate it. :3