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mateoniksic3
2,255 PointsWhat kind of question is this?
?
3 Answers
Jeff Muday
Treehouse Moderator 28,722 Pointsactually-- the only thing you are supposed to type in is [:]
It stumped me the first time too. I feel they left out the '=' sign. I noted the issue to the Treehouse staff so at some point it will be changed to be similar to what you typed above.
Good luck with your Python journey!!
Jeff Muday
Treehouse Moderator 28,722 PointsAre you referring to the slice copy question? That's the only question that is slightly odd.
Since a list is "mutable" you have to make sure your copy a list if you want to keep it intact. As an example, if I take a list x and check its id() then I assign y equal to x, then I check its id(). You will notice the ids are the same (they are the same list!) so if I change y[0] = 'Hello', you will see x[0] is also 'Hello'
Python 3.7.1 (v3.7.1:260ec2c36a, Oct 20 2018, 14:57:15) [MSC v.1915 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> x = [1,2,3,4]
>>> x
[1, 2, 3, 4]
>>> id(x)
1416993727112
>>> y = x
>>> id(y)
1416993727112
>>> y[0] = 'Hello'
>>> x
['Hello', 2, 3, 4]
But, we can copy a list with a slice y=x[:] it looks strange, but accomplishes creating a COPY of the list (with an entirely different memory id). Now... when we change y[0] = 'Hello', notice that x is NOT CHANGED.
Python 3.7.1 (v3.7.1:260ec2c36a, Oct 20 2018, 14:57:15) [MSC v.1915 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> x = [1,2,3,4]
>>> id(x)
2777124397704
>>> y = x[:]
>>> id(y)
2777124886984
>>> y[0] = 'Hello'
>>> y
['Hello', 2, 3, 4]
>>> x
[1, 2, 3, 4]
mateoniksic3
2,255 PointsI'm refering to that question and I know the answer, but it does not work and it does not make sense.
It says copy this list for e.g.
X = [1,2,3,4,5]
X = __________
So it wants me to make it look like X = X[:] ??
mateoniksic3
2,255 PointsThank you Jeff!