why does accumulate increments value in defined manner(adding the previous list values only with natural numbers)?

Question

Is there alternate for it?

Answer 1

What do you mean by why?
I am not sure if you know this already.
from itertools import accumulate, takewhile
nums = list(accumulate(range(8)))
print(nums)
_________________
[0, 1, 3, 6, 10, 15, 21, 28]
range function makes
[0,1,2,3,4,5,6,7]
and accumulate function does
[0,0+1,0+1+2,0+1+2+3,0+1+2+3+4,and so on] #it adds previous list items
this equals to [0,1,3,6,10,15, etc]

Answer 2

The other way to do this is to
use def function(i think you know this already)