foo.md

Sum elements to next in a list

Question:

I have to create a function that sums of every 2 consecutives elements ina lst. for example ([2,4,3,1,-2]). the output expected [6,7,4,-1]

The basic idea is to take the collection

2

4

3

1

-2

and a copy of it that skips the first element (islice is a good fit for this)

from itertools import islice
return list(islice(lst, 1, None))

4

3

1

-2

You then zip the two together into a tuple

return list(zip(lst, skipped))

2	4
4	3
3	1
1	-2

Now it's just a matter of iterating each tuple and adding the two elements

return list(a+b for a,b in zipped)

So putting it all together, it's a one liner

from itertools import islice
return list(a+b for a,b in zip(lst, islice(lst, 1, None)))

6

7

4

-1