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Python Introducing Lists Build an Application Multidimensional Musical Groups

Posted by Alana Warson
Alana Warson
5,296 Points

here is a multi-dimensional list of musical groups. The first dimension is group, the second is group members.

This multidimensional lists was covered in the last portion of videos I watched. Why can't questions and challenged be in the same track of videos that we are currently going over, Therefore, I have no idea of trying to loop through via dimensions and output members. Can I please get help? Is there an easier track besides Python?

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

6 Answers

Peter Vann
Peter Vann
36,427 Points
Peter Vann
Peter Vann
36,427 Points

Hi Alana!

Happy Easter (if you're into that sort of thing)!!! (I spent today visiting my Mom!?!)

This whole challenge is just exploring nested/2-dimensional lists (a list of lists).

Also, it helps to understand how the Python join works (which is essentially BACKWARDS from how you would code it in JavaScript).

More info:

https://www.w3schools.com/python/ref_string_join.asp

And then, of course a for/in loop would be a good looping structure.

This passes task 1:

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) ) # "group" being a list of members

But now you have to filter the groups and only print the ones with 3 members (Hint: You'll need to add an if statement).

Sidebar: I try to spend equal time on JS, Python, and PHP (and HTML and CSS) - they all have their place!

Lemmeeno if you can figure out task 2.

If not, I'll help you further.

I hope that helps.

Stay safe and happy coding!

Alana Warson
Alana Warson
5,296 Points
Alana Warson
Alana Warson
5,296 Points

Ah, Happy Easter too! I celebrate some holidays but usually try to stay away from my dysfunctional family 😁 My first line of code was: for musical groups in musical groups. Thank you for your help again. Have a great day!

Alana Warson
Alana Warson
5,296 Points
Alana Warson
Alana Warson
5,296 Points

OK, I wrote the code you showed and I got an invalid syntax. I went back and copy/paste your code and I still got a syntax error.

Peter Vann
Peter Vann
36,427 Points
Peter Vann
Peter Vann
36,427 Points

Hi Alana!

This passed task 1 for me:

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_members in musical_groups:
    print( ", ".join(group_members) )

(I changed group to goup_members for clarity.)

At first, it didn't pass because somehow my first line became:

mmusical_groups = [

(Note the mistake: double mm)

(A copy-n-paste error, evidently...)

This passes task 2:

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_members in musical_groups:
    if len(group_members) == 3: #  filters-out all but the 3-member groups
        print( ", ".join(group_members) )

I hope that helps.

Stay safe and happy coding!

Alana Warson
Alana Warson
5,296 Points
Alana Warson
Alana Warson
5,296 Points

Ok the funny thing ... I cannot find the track this problem was at.

Alana

Peter Vann
Peter Vann
36,427 Points
Peter Vann
Peter Vann
36,427 Points

Hi Alana!

Try here:

https://teamtreehouse.com/library/introducing-lists

https://teamtreehouse.com/library/introducing-lists/build-an-application/multidimensional-musical-groups

I hope that helps.

Stay safe and happy coding!

Riley Ittidecharchoti
Riley Ittidecharchoti
3,195 Points

Thanks for this... I almost had it!