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Lyric Abbott
35,595 Pointshelp
fill in the blank
Copy the entire list with a slice.
a_list = [1, 2, 3]
my code:
a_list=[1:3] [2, 3]
21 Answers
Nicholas Olsen
Front End Web Development Techdegree Student 19,342 PointsArrays start with an index of 0. Also, the first number in the slice is inclusive while the second number is exclusive. So the proper slice would be
a_list[0:3]
Ron Kopald
785 PointsHmm, I tried all of those things and I'm still getting "Incorrect"
nvcxnvkldsjaklfds
Courses Plus Student 5,041 PointsAs Nicholas Olsen said, index starts at 0 and goes upto len()-1.
You can also slice list with following syntax. By just adding starting index, you are explicitly telling that take from starting index to all the way up to len(a_list)-1
a_list[0:]
Other way would be just specifying the end index. In the below syntax, you are just specifying ending index meaning you are telling I want all the element from starting index (default 0) to all the way up to 3.
a_list[:3]
I hope it helps. If you have any questions please feel free to ask here.
Kenneth Love
Treehouse Guest Teachera_list[:] works too because the 0 is implied.
nvcxnvkldsjaklfds
Courses Plus Student 5,041 PointsBut doesn't it create a copy of a_list? Does copy of a list variable equal list variable?
Kenneth Love
Treehouse Guest TeacherYes, a_list[:] creates a copy of the list variable. But a_list[0:] also creates a copy of the list. In fact, they create the exact same copy of the list.
(To be 100% accurate, though, neither creates a copy of the list. Rather they create a slice from the list that happens to be 100% of the list.)
Isaac Henry
15,541 Pointsi need help my code is
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 = [1, 2, 3] slice1[:3]
and on top of that i tried all of your answers
Kenneth Love
Treehouse Guest TeacherThis thread relates to the old version of the course. What problem are you having?
Ron Kopald
785 Pointsa_list = [1, 2, 3]
a_list = a_list[:]
Correct?
Ron Kopald
785 PointsThanks. I missed the subtlety of that. (do'h)
Isaac Henry
15,541 Pointsslice1 = [1, 2, 3] slice1[0:3]
Kenneth Love
Treehouse Guest TeacherHmm, no. That makes a list named slice1 and then makes a slice that has the entire contents of it in it. This is a great thing to try out in your Python shell
Isaac Henry
15,541 Pointsbut it says to make a varible named slice1
Kenneth Love
Treehouse Guest TeacherIt says
Create a new variable named
slice1that has the second, third, and fourth items fromfavorite_things.
So, yes, you make a variable named slice1 but it doesn't say that slice1 is a list or that it should have the numbers 1, 2, and 3 in it.
Isaac Henry
15,541 Pointsis'nt it slice1 = favorite_things[1, 2, 3]
Kenneth Love
Treehouse Guest Teacherfavorite_things[1, 2, 3] isn't the slice syntax. Slices use a colon.
Isaac Henry
15,541 Pointsor slice1 = [1, 2, 3]
Isaac Henry
15,541 Pointsso like favorite_things[1:, 2:, 3:]?
Kenneth Love
Treehouse Guest TeacherMaybe instead of guessing, go watch the video again. There's no shame in rewatching content
Isaac Henry
15,541 Pointsok
Isaac Henry
15,541 Pointsit's confusing
Isaac Henry
15,541 Pointshardest challenge i went through
Isaac Henry
15,541 Pointsso far
Isaac Henry
15,541 Pointskenneth i watched the video twice and still very confusing
Ken Alger
Treehouse TeacherIsaac;
You are using this as your list, correct?
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']
And the task calls for us to utilize the slice syntax and put the 2nd, 3rd, and 4th items into a new variable called slice1, correct?
So we would need to do something for:
slice1= <some slice syntax here>
In watching the videos, how do we slice lists in Python? If we have a list and want to capture the fifth, sixth, and seventh items in the list we would do our_list[4:7], correct? The 4 representing where we want to start our slice and the 7 representing the item after we want to stop, therefore, in this example we would be capturing items 5, 6, and 7.
Our task then, is to apply that same concept and similar syntax to this task.
The concept of slicing lists is an important one to have a good handle on and it is great that you are working your way through it and asking questions! Post back if you are still stuck and feel free to ask additional questions.
Ken
Joe Arcaro
2,433 PointsGuys,
This is getting frustrating ...
I gave the answer [:] (without a leading space!) and it failed me the first two times. On the third try it worked.
And the previous exercises can't be completed for this very same reason. Even copy pasting the correct answer from help section does not work . (Slice functions question 2 fails regardless ...)
nvcxnvkldsjaklfds
Courses Plus Student 5,041 PointsPlease check few more things:
- Did you spell the variable name correctly,
- There is no space between variable name and [], for example a_list[:]
- There is colon between inside the square brackets.
I hope this helps and if you does not work after all this please post your code here.
nvcxnvkldsjaklfds
Courses Plus Student 5,041 PointsRon Kopald Thanks for your code. All you have to do is just fill the blank with the [](square brackets) with slice that copies the entire list.
You do not need to assign the value the slice to a_list variable.
So basically, fill blank with [:]. You will be fine. I hope it helps.
ellie adam
26,377 Pointsa_list = [1, 2, 3]
a_list[:3]
Isaac Henry
15,541 PointsKenneth i typed in the following answers and they are not working
Kenneth Love
Treehouse Guest Teacherslice1 should have the 2nd, 3rd, and 4th items from favorite_things. Lists, which favorite_things is, are 0-indexed, so the first item has index of 0. What would be the indexes for items 2, 3, and 4?