sum accuracy

[Peter Otten]

Robin Becker wrote:

> Does anyone know if sum does anything special to try and improve accuracy?
> My simple tests seem to show it is exactly equivalent to a for loop
> summation.

If you are worried about accuracy and your values are floating point numbers 
use math.fsum():

"""
fsum(...)
    fsum(iterable)
    
    Return an accurate floating point sum of values in the iterable.
    Assumes IEEE-754 floating point arithmetic.
"""