Finding the difference between consecutive numbers in a list (Python)

Question

Given a list of numbers, I am trying to write a code that finds the difference between consecutive elements. For instance, A = [1, 10, 100, 50, 40] so the outp

Answer 1

Actually recursion is an overkill:

def deviation(A):
    yield 0
    for i in range(len(A) - 1):
        yield abs(A[i+1] - A[i])

Example:

>>> A = [3, 5, 2]
>>> list(deviation(A))
[0, 2, 3]

EDIT: Yet, another, even simplier and more efficient solution would be this:

def deviation(A):
    prev = A[0]
    for el in A:
        yield abs(el - prev)
        prev = el