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Python Introducing Lists Build an Application Multidimensional Musical Groups

Posted by sarabahrini
sarabahrini
5,493 Points

Joining 2 dimensional lists - Python

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

Can you loop through each group and output the members joined together with a ", " comma space as a separator, please?

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"], ]

What is wrong with my answer below and how to fix it(?):

for group in musical_groups: ", ".join(group)

print(", ". join(musical_groups))

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 group in musical_groups:
    ", ".join(group)

print(", ". join(musical_groups))

2 Answers

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,423 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points

You are close on the first task. Print the result of the join() inside the for loop.

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

sarabahrini
sarabahrini
5,493 Points

It worked!! Thank you :)

cesarmatta
cesarmatta
11,308 Points
cesarmatta
cesarmatta
11,308 Points

Why is it usefull to repeat the", ".join(group) ? I think you can just do like that: 

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))