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

Simon Au
Simon Au
5,508 Points

How to join a separator in a multidimensional list?

I ran into error on line 13. It said musical_groups is undefined.

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


to_line = ", ".join(muscial_groups) 
group_number = 1
for group in musical_groups:
    print( "* group #{}: {}".format(group_number, to_line))
    group_number += 1

1 Answer

Alexander Besse
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Alexander Besse
Full Stack JavaScript Techdegree Graduate 35,115 Points

Hi Simon!

I took a run through your code and here is the conclusion I found. Take a look at my code, make sure you understand it and compare the differences between itself and your code.

for group in musical_groups:
    members = []
    for member in group:
        members.append(member)
    print(", ".join(members))

Hope this helps, let my know if you have questions!

Simon Au
Simon Au
5,508 Points

Thank you Alex! This answered my question.