a[x:y:z] gives the same result as a[slice(x, y, z)]. One of the advantages of a slice object is that it can be stored and retrieved later as a single object instead of storing x, y and z. It is often used to let the user define their own slice that can later be applied on … Read more
Yes, if j <= i is true, the resulting slice is empty, for standard Python types. To get the results in reverse order, you need to add a negative stride: list[i:j:-1] because explicit is better than implicit. This is documented in Common Sequence Operations, footnote 4: The slice of s from i to j is … Read more
Try itertools.islice(). deque_slice = collections.deque(itertools.islice(my_deque, 10, 20)) Indexing into a deque requires following a linked list from the beginning each time, so the islice() approach, skipping items to get to the start of the slice, will give the best possible performance (better than coding it as an index operation for each element). You could easily … Read more
groovy:000> sliceMe = “nnYYYYYYnnnnnnnnnn” ===> nnYYYYYYnnnnnnnnnn groovy:000> sliceMe[2..7] ===> YYYYYY Note the difference in the length being 1 less.
The built in method copy will only copy a slice to a slice NOT a slice to an array. You must trick copy into thinking the array is a slice copy(varLead.Magic[:], someSlice[0:4]) Or use a for loop to do the copy: for index, b := range someSlice { varLead.Magic[index] = b } Or do as … Read more
There’s an easier way to do this (at least in 3.4, I don’t have 3.3 at the moment, and I don’t see it in the changelog). Assuming your class already has a known length you can just slice a range of that size: >>> range(10)[1:5:2] range(1, 5, 2) >>> list(range(10)[1:5:2]) [1, 3] If you don’t … Read more
As of version 1.8, you can use the simpler function sort.Slice. In your case, it would be something like the following: sort.Slice(dirRange, func(i, j int) bool { return dirRange[i] < dirRange[j] }) This avoids having to define any type just for the sorting.
You can set the length property of the array. var input = [‘a’,’b’,’c’,’d’,’e’,’f’]; input.length = 1; console.log(input); OR, Use splice(startIndex) method var input = [‘a’,’b’,’c’,’d’,’e’,’f’]; input.splice(1); console.log(input); OR use Array.slice method var input = [‘a’,’b’,’c’,’d’,’e’,’f’]; var output = input.slice(0, 1) // 0-startIndex, 1 – endIndex console.log(output);
I’ve got two one liners. Given: >>> letters = [‘a’,’b’,’c’,’d’,’e’,’f’,’g’,’h’,’i’,’j’] Use enumerate to get index, add ‘x’ every 3rd letter, eg: mod(n, 3) == 2, then concatenate into string and list() it. >>> list(”.join(l + ‘x’ * (n % 3 == 2) for n, l in enumerate(letters))) [‘a’, ‘b’, ‘c’, ‘x’, ‘d’, ‘e’, ‘f’, ‘x’, … Read more
For your first example, I would do: mySlice := make([]*UselessStruct, 5) for i := range mySlice { mySlice[i] = new(UselessStruct) } The issue you are facing in both examples is you are appending to a slice that is already the correct length. If you set mySlice := make([]*UselessStruct, 5), you are asking for a slice … Read more