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

Adam Davis
Adam Davis
862 Points
Posted by Adam Davis
Adam Davis
862 Points

Python Collections: Back and Fourth: Challenge Task 3 of 3 Bummer?

I don't know why this code fails. 

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 = []
slice2 = []

slice1.insert(0, favorite_things.pop(1))
slice1.insert(1, favorite_things.pop(1))
slice1.insert(2, favorite_things.pop(1))

slice2.insert(0, favorite_things.pop(-2))
slice2.insert(1, favorite_things.pop(-1))

print(slice1)
print(slice2)
print(favorite_things)

sorted_things = favorite_things[:]
sorted_things.sort()

print(sorted_things)
print(favorite_things)
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 = []
slice2 = []

slice1.insert(0, favorite_things.pop(1))
slice1.insert(1, favorite_things.pop(1))
slice1.insert(2, favorite_things.pop(1))

slice2.insert(0, favorite_things.pop(-2))
slice2.insert(1, favorite_things.pop(-1))

print(slice1)
print(slice2)

sorted_things = favorite_things[:]
sorted_things.sort()

print(sorted_things)
print(favorite_things)

1 Answer

Steven Parker
Steven Parker
231,269 Points
Steven Parker
Steven Parker
231,269 Points

The challenge isn't expecting you to change the original list. When they say "get" items from it, they mean "get copies".

The challenge is also intended to give you opportunities to use slices, and while the technique you used for tasks 1 and 2 generates the correct results, you're not really getting the intended benefit of the challenge. Also, if you used slices to solve the tasks the issue of altering the original list would not have come up.

Try starting over, you might be surprised at how much more compact the code will be using the slices.