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

Posted by Chris Drummond
Chris Drummond
1,315 Points

having issues bring the music groups with only 3 members

I keep getting an AssertionError. I haven't been able to find the solution to this one.

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 band in musical_groups:
    seperator = ", "
    bands = seperator.join(band)
    print(bands)

for members in musical_groups:
    if len(members) == '3':
       print(", " .join(members))

1 Answer

Jennifer Nordell
seal-mask
STAFF
.a{fill-rule:evenodd;}techdegree
Jennifer Nordell
Treehouse Teacher
Jennifer Nordell
.a{fill-rule:evenodd;}techdegree
Jennifer Nordell
Treehouse Teacher

Hi there, Chris Drummond ! You're doing great! Part of the problem here is that you now have two loops. For the second step you were meant to alter the first loop.

This one is very close:

for members in musical_groups:
    if len(members) == '3':
       print(", " .join(members))

However, you're comparing the length to the string'3' instead of the integer 3. So where you have:

    if len(members) == '3':

I'm expecting:

    if len(members) == 3:

The len() function will always return an integer.

Hope this helps! :sparkles: