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

harpreet grewal
harpreet grewal
19,018 Points
Posted by harpreet grewal
harpreet grewal
19,018 Points

i dont understand what im doing wrong

it keeps saying im trying to sort favorite_things

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[5:7]

sorted_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[5:7]

sorted_things = favorite_things
sorted_things.sort()

3 Answers

leonardbode
leonardbode
Courses Plus Student 4,011 Points

Hey Harpreet,

Check out my code, I edited your code and added comments:

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:]

# notice the [:]
sorted_things = favorite_things[:]
sorted_things.sort()

Notice the [:], we need this because without it you would be changing the variable name of favorite_things instead of assigning a copy "[:]" of favorite_things.

If you have any other questions I will update my answer, if you do not have any other questions:

Remember to upvote and to choose the best answer so that your question receives a checkmark in forums.

Kind regards,

Leo

Alexander Davison
Alexander Davison
65,469 Points
Alexander Davison
Alexander Davison
65,469 Points

You have to add a [:] after the sorted_things = favorite_things so it looks like this: sorted_things = favorite_things[:].

This is because in your original script, you assign the sorted_things variable to point to the same point in memory as favorite_things, not to get the value of favorite_things and assign it to sorted_things. So, this means if you edit either lists, both lists will be changed in place since they point to the same place in memory. You can use [:] to get the a copy if the list.

I hope you understand. ~Alex

Don't worry if you don't completely understand; this is a very confusing thing in computer science. Just remember to add [:] if you want to set variable to another variable containing a list.

harpreet grewal
harpreet grewal
19,018 Points
harpreet grewal
harpreet grewal
19,018 Points

Thank You Leonard and Alex!