Python Introducing Lists Build an Application Multidimensional Musical Groups

Shane Smith
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Shane Smith
Python Development Techdegree Student 1,555 Points

Challenge help... again

Hi, me AGAIN ... Not sure what my error is in this challenge.

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"],
]
for group in musical_groups:
    if len(group) == 2:
        seperator = ", "
        print(seperator.join(group))

1 Answer

rydavim
MOD
rydavim
Treehouse Moderator 18,641 Points

Looks like you've got all the important bits correct. It looks like you might be used to working with 0 as a start (which is common) and Python len() works more like counting.

for group in musical_groups:
  if len(group) == 2: # trios really do = 3 here
    seperator = ", "
    print(seperator.join(group))

That's a pretty common and totally reasonable confusion when you're new to programming. Lots of stuff - like indexes start from 0, but here you're looking for a length of 3. Everything else looks good!