Is there a pythonic way to get two elements from the list (first, second)...(last, first)

Question

def convert_number_into_months_range(number):
    zodiac_months = [3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 1, 2]
    first_month = zodiac_months[number]
    if number == len(zodiac_months) - 1:
        second_month = zodiac_months[0]
    else:
        second_month = zodiac_months[number + 1]
    return first_month, second_month

This is my example. It works, but looks unpythonic. On Input we have an index of the list. On return we have tuple of (index, index+1) elements of the list. If the index is pointing on the last element then we should get (last, first) elements. Is there are way to do it in more pythonicaly?

Use `(number + 1) % len(zodiac_months)` to produce `0` when `number` is the last index. — Martijn Pieters, Feb 13 '19 at 14:43

Taohidul Islam · Accepted Answer · 2019-02-13T14:54:09.893

0

You can try this:

def convert_number_into_months_range(number):
    zodiac_months = [3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 1, 2]
    return zodiac_months[number], zodiac_months[(number + 1) % len(zodiac_months)])

edited Feb 13 '19 at 14:54

answered Feb 13 '19 at 14:45

Taohidul Islam

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down vote? But why? – Taohidul Islam Feb 13 '19 at 14:52
1

The return should be `return zodiac_months[number], zodiac_months[(number + 1) % len(zodiac_months)]` so that the indexing does not depend on the values of the list. (I am not the downvoter.) – Dan D. Feb 13 '19 at 14:52
Oh! how have I missed that! updated, thanks :) – Taohidul Islam Feb 13 '19 at 14:54
Thank you guys! I've one more way that is very specific to Python: – ggguser Feb 13 '19 at 15:41
`second_month = zodiac_months[number + 1 - len(zodiac_months)]` Here we use negative indexing, calculating the second number from the right side of the list. – ggguser Feb 13 '19 at 15:48

Is there a pythonic way to get two elements from the list (first, second)...(last, first)

1 Answers1