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

Python Python Collections (2016, retired 2019) Slices Back and Forth

Posted by Joe Mackey
Joe Mackey
20,418 Points

Alright, let's make this last step a bit harder and do two things. Make a copy of favorite_things

I made a copy of favorite_things favorite_things=sorted_things[:].sort()

slices.py 
favorite_things = ['raindrops on roses', 'whiskers on kittens', 'bright copper kettles',
                   'warm woolen mittens', 'bright paper packages tied up with string',
                   'cream colored ponies', 'crisp apple strudels']
slice1 = favorite_things[1:4]
slice2 = favorite_things[-2:]
favorite_things=sorted_things[:].sort() # added line 6 and Task 1 is no longer passing ??? 
                                        # make a copy of favorite_things and call it sorted_things then sort. Tried with and without the [:]
                                        # I am missing something here, any reading suggestions?

1 Answer

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,457 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,457 Points

Since the list method .sort() operates on a list in-place a copy needs to be made before it can be sorted. The line:

favorite_things=sorted_things[:].sort()

is trying to make a copy of sorted_things which has not yet been defined. The correct approach is using two steps:

  • define sorted_things as a slice copy of favorite_things
  • run the sort method directly using sorted_things.sort()

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