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Python Introducing Lists Build an Application Multidimensional Musical Groups

Grayden Kellogg
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Grayden Kellogg
Python Development Techdegree Student 1,826 Points
Posted by Grayden Kellogg
.a{fill-rule:evenodd;}techdegree
Grayden Kellogg
Python Development Techdegree Student 1,826 Points

Printing lists that have 3 objects from a multidimensional list.

My output is showing the desired result but I am getting an error that I don't understand.

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 groups in musical_groups:
    musical_groups2 = ", ".join(groups)
    if len(groups) == 3:
        print(groups)

4 Answers

Steven Parker
Steven Parker
231,268 Points
Steven Parker
Steven Parker
231,268 Points

The selection logic is fine. But I'm guessing you intended to print out the formatted version of the list (musical_groups2) instead of the raw list (groups).

MICHAEL WANSLEY
MICHAEL WANSLEY
1,229 Points
MICHAEL WANSLEY
MICHAEL WANSLEY
1,229 Points

I'm not sure why I can pass the first part of the challenge but not the trio section, even though the second for loop prints the correct group names.

```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"], ]

s = ", " band = []

for groups in musical_groups: band = s.join(groups) print(band)

for i in musical_groups: if len(i) == 3: print(str(i) + " are part of a trio.")

Steven Parker
Steven Parker
231,268 Points
Steven Parker
Steven Parker
231,268 Points

This is one of the rare occasions where the instructions tell you to modify the code from the previous step. So after task 2, there should still be only one loop.

And for future issues, always start a new question instead of asking one in an "answer". That will give you a better chance to be seen by more students and get a rapid reply.

MICHAEL WANSLEY
MICHAEL WANSLEY
1,229 Points
MICHAEL WANSLEY
MICHAEL WANSLEY
1,229 Points

This is the error message I get. There doesn't seem to be an easy way to upload a screen shot...

"Bummer: AssertionError: 'Ad Rock, MCA, Mike D.' not found in "['Ad Rock', 'MCA', 'Mike D.']\n['Salt', 'Peppa', 'Spinderella']\n['Run', 'DMC', 'Jam Master Jay']" : Hmmm...I'm not getting the output I expected."

MICHAEL WANSLEY
MICHAEL WANSLEY
1,229 Points
MICHAEL WANSLEY
MICHAEL WANSLEY
1,229 Points

AH HAAAAAA!!! The answer is, print the value of the .join()!!!! It'd be nice if the req was a bit more informative. But that's just my 'manual tester mind' bitchin about documentation again, LOL!!!!