Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

Python Introducing Lists Build an Application Multidimensional Musical Groups

Vashisth Bhatt
seal-mask
.a{fill-rule:evenodd;}techdegree
Vashisth Bhatt
Python Web Development Techdegree Student 6,786 Points

why it is throwing assertion error

:-group_number=1 for group in musical_groups: string = " ".join(group) print("

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"],
]
group_number=1
for group in musical_groups:
    string = " ".join(group)
    print("Group #{}:{}".format(group_number,string))
    group_number=group_number+1

2 Answers

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

Hi there, Vashisth Bhatt ! You're doing terrific and your logic is spot on! However, you've done a print here that is way fancier than what the challenge asked for. You're printing out the group members separated by a space and even included the group number as it goes through the list! Remember, when these challenges ask you to print something, or return a string, it must be exactly what the challenge is expecting or it will fail. Essentially, you need to make your string match the challenge specifications which state that it should simply print the group members separated by a comma and a space.

So if I remove some of your code and instead do this:

string = ", ".join(group)
print(string)

... your code passes with flying colors!

Hope this helps! :sparkles:

Vashisth Bhatt
seal-mask
.a{fill-rule:evenodd;}techdegree
Vashisth Bhatt
Python Web Development Techdegree Student 6,786 Points

Thanks a lot @Jeniffer.I have another question for 2nd challenge.it is againgiving me this error:- IndentationError: unindent does not match any outer indentation level

Can you please why this error is coming and at what time and instance this error appear? 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: string = ", ".join(group) lits=string.split(", ") if(len(lits)==3): print(lits)