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Python Introducing Lists Build an Application Multidimensional Musical Groups

Posted by Alberto Serafini
Alberto Serafini
1,211 Points

Python's lists last challenge.

Hi everybody! I'm not able to find the solution to the last problem. here's what I tried:

for group in musical_groups :
      print(", ".join([member for member in group if len(member) == 3]))

Please Help!

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 :
    print(", ".join([member for member in group if len(member) == 3]))

4 Answers

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

You won't need anything this fancy. Plus, this will print out empty lists when the size is other than 3.

The simple approach is to just put an "if" before the "print" that was already there from task 1, so that it only runs when the list has 3 members.

Ave Nurme
Ave Nurme
20,907 Points
Ave Nurme
Ave Nurme
20,907 Points

Hey Alberto

I think you need to find trios that is groups which consist of 3 members so I think that len(group) might be useful. I solved the challenge without list comprehension. At first I iterated through the groups in musical_groups and checked the length of each group. If the length was 3 (as in 3 members) I joined them into a string separated by a comma.

Alberto Serafini
Alberto Serafini
1,211 Points
Alberto Serafini
Alberto Serafini
1,211 Points

Thank you Ave and thank you Steven! Yes, I think I went too far with list comprehension and now I'm a bit lost. I'll try to follow the hints you gave me and then I'll let you know how it goes. thanks!!

Alberto Serafini
Alberto Serafini
1,211 Points
Alberto Serafini
Alberto Serafini
1,211 Points

Thank you so much Steven! You made my day! Here's what i did:

for group in musical_groups:
     if len(group) == 3:
        print(", ".join(group))

Do you have any advice for me to do a better job of looking for the most simple solution, instead of over-complicating things? what should I work on? Thank you so much again!

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

Three suggestions: practice, practice, and practice. :wink: