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 Jessica Fowler
Jessica Fowler
8,462 Points

Why isn’t this working??!?! Confounded!

Awesome! Now I'd like to see only groups that are trios, you know 3 members. So can you please only print out the trios? It should still use the joined string format from task 1.

groups.py
KRIS NIKOLAISEN
KRIS NIKOLAISEN
54,971 Points

Can you post your code?

Jessica Fowler
Jessica Fowler
8,462 Points

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"], ]

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

3 Answers

KRIS NIKOLAISEN
KRIS NIKOLAISEN
54,971 Points

For task 2 you only want to print the groups that meet your if condition. Remove the print statement above this and you are good.

Jessica Fowler
Jessica Fowler
8,462 Points

thanks. That worked!

diginoma
PLUS
diginoma
Courses Plus Student 8,009 Points
diginoma
diginoma
Courses Plus Student 8,009 Points

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 group in musical_groups: if len(group) == 3: # to selects lists that only have 3 items print(", ".join(group))

Anupam Kumar
Anupam Kumar
3,795 Points
Anupam Kumar
Anupam Kumar
3,795 Points

I am not sure what is getting wrong with this, can someone help me with this. 

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

for group in musical_groups:
    if len(group) == 3:
        print(", ".join(group))
Luis Gutierrez
seal-mask
.a{fill-rule:evenodd;}techdegree
Luis Gutierrez
Python Development Techdegree Student 2,131 Points
Luis Gutierrez
.a{fill-rule:evenodd;}techdegree
Luis Gutierrez
Python Development Techdegree Student 2,131 Points

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"], ]

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

???