how can i do math operation on list elements in python?

Question

Suppose i have list of numbers [3, 51, 34]. I want to add to each element the sum of the previous elements and return a new list with these new values. So here the

Answer 1

And a trivial, procedural solution, for completeness:

a = [3,51,34]

def cumsum(numbers):
  accum = 0
  result = []
  for n in numbers:
    accum += n
    result.append(accum)
  return result

print cumsum(a)

It prints [3, 54, 88]