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![](https://ecs-static.teamtreehouse.com/assets/views/marketing/shared/community-banner-white-47072046c51352fe6a69f5e691ff5700b28bb11d45197d7bdf066d9ea3f72d0c.webp)
![Edward Randall](https://secure.gravatar.com/avatar/7d718bba9c92f9be292e50ca5454540d?s=96&d=https%3A%2F%2Fecs-static.teamtreehouse.com%2Fassets%2Fcontent%2Fdefault_avatar-445fbbabfc8dc9188fb5967fe43322ee0c3e0dd1e10f378bf8343784af5a13eb.webp&r=pg)
Edward Randall
1,834 PointsHow do I do this problem?
How do I do this problem?
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_groups
print[0][0]
1 Answer
![Chris Freeman](https://uploads.teamtreehouse.com/production/profile-photos/1153532/micro_image.jpg)
Chris Freeman
Treehouse Moderator 68,425 PointsHey Edward Randall, let’s break down the task:
The given outer list contains group members contained in a list, aka a list-of-lists.
- Can you loop through each group [in the outer list]...
This is the usual loop through a list:
for inner_list in outer_list:
- output the members joined together with a ", " comma space as a separator
A list can be joined together into a string using the str.join()
method. This uses a string as the glue characters between a list of strings. So,
“, “.join(inner_list)
Creates a larger string with inner_list items comma-space separated.
Post back if you need more help. Good luck!!!