Python - Create a new sublist between two elements in an ordered list

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Given two elements in an ordered list, I want to make a new list consisting of everything between (and including) those elements. The problem comes if the second point comes before the first point in the list. right is my existing sorted list of objects. rt is the beginning boundary and rb is the end boundary. new_right = right[right.index(rt): right.index(rb) + 1]

This snippet works except in the case

right = [a, rb, c, rt, d, e]

where I get [rt, d, e] instead of the wrapped [rt, d, e, a, rb]

Is there a way to do this without creating a complicated method? Some other people's problems were solved by list comprehension. Looking into it, I was able to come up with

begin = right.index(rt)
end = right.index(rb)
if end > begin:
    new_right = right[begin: end + 1]
else:
    new_right = [right[i % r_len] for i in range(begin, r_len + end + 1)]

Which looks pretty ugly to me, but it seems to hold up to my tests. Is there a better way to do this?

EDIT: There were two working solutions to this.

rbegin = right.index(rt)
rend = right.index(rb)
if rend >= rbegin:
    new_right = right[rbegin: rend + 1]
else:
    new_right = [right[i % r_len] for i in range(rbegin, r_len + rend + 1)]

Which is obscenely complicated compared to:

if rend > rbegin:
    new_right = right[rbegin: rend + 1]
else:
    new_right = right[rbegin:] + right[:rend + 1]

Would simply flipping the slice match your tests like so:

begin = right.index(rt)
end = right.index(rb)
if end > begin:
    new_right = right[begin: end + 1]
else:
    new_right = right[end: begin + 1]

Python, Given a list of lists, write a Python program to extract first element of each sublist in the given list of lists. Examples: Input : [[1, 2], [3, 4, 5], [6, 7, 8,� I have a list of lists in the form: list = [[3, 1], [3, 2], [3, 3]] And I want to split it into two lists, one with the x values of each sublist and one with the y values of each sublist. I


Maybe this?

new_right = right[begin: end + 1] if end > begin else right[begin:] + right[:end + 1]

Python, GBlog � Puzzles � What's New ? element in a sorted and rotated array � Reversal algorithm for right rotation of an array Approach will be run two nested loop till the length of the given list. all elements on right of the picked elements as ending element of subarray. function to generate all the sub lists. The outer loop picks starting element and inner loop considers all elements on right of the picked elements as ending element of subarray. To get the subarray we can use slicing to get the subarray. Step 1: Run a loop till length of the given list.


You can add the trailing and leading slices instead of using a comprehension. Using your code structure:

begin = right.index(rt)
end = right.index(rb)
if end > begin:
    new_right = right[begin: end + 1]
else:
    new_right = right[begin:] + right[:end + 1]

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