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

Zhang Dong Zhi
Zhang Dong Zhi
982 Points
Posted by Zhang Dong Zhi
Zhang Dong Zhi
982 Points

multidimensional musical groups task two of two

i dont know how to do this,can someone please teach me.thank you very much

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 musical_group in musical_groups:
     print(', '.join(musical_group))

1 Answer

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,457 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,457 Points

You are on the right path. For Task 2, insert an if statement to verify if the musical_group has three members. The len() function works well here.

Post back if you need more help. Good luck!!!

Zhang Dong Zhi
Zhang Dong Zhi
982 Points
Zhang Dong Zhi
Zhang Dong Zhi
982 Points

if len((musical_group)) == 3: print(musical_group)

I tried this but this is wrong what did i do wrong and what should i do

Chris Freeman
Chris Freeman
Treehouse Moderator 68,457 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,457 Points

The if statement is correct, though the double parens should be single parens. Be sure to indent the print statement to be inside the if code block.

Zhang Dong Zhi
Zhang Dong Zhi
982 Points
Zhang Dong Zhi
Zhang Dong Zhi
982 Points

sorry if i dont quite get what is paren so do you mean by putting the code in two line?

Chris Freeman
Chris Freeman
Treehouse Moderator 68,457 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,457 Points

Sorry for the jargon use. Paren is short for parenthesis. 

    if len(musical_group) == 3:  # single parens is sufficient
        print(', '.join(musical_group))