Python - Create a new sublist between two elements in an ordered list
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
new_right = right[begin: end + 1] if end > begin else right[begin:] + right[:end + 1]
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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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