Iterate a list as pair (current, next) in Python

Question

I sometimes need to iterate a list in Python looking at the \"current\" element and the \"next\" element. I have, till now, done so with code like:

for curre         


        

Answer 1

This is now a simple Import As of 16th May 2020

from more_itertools import pairwise
for current, next in pairwise(your_iterable):
  print(f'Current = {current}, next = {nxt}')

Docs for more-itertools Under the hood this code is the same as that in the other answers, but I much prefer imports when available.

If you don't already have it installed then: pip install more-itertools

Example

For instance if you had the fibbonnacci sequence, you could calculate the ratios of subsequent pairs as:

from more_itertools import pairwise
fib= [1,1,2,3,5,8,13]
for current, nxt in pairwise(fib):
    ratio=current/nxt
    print(f'Curent = {current}, next = {nxt}, ratio = {ratio} ')