Python fsum() function is similar to sum() function, returns the sum. However, fsum() returns the value keeping higher floating accuracy. fsum() takes an iterable as its argument. It's a method of math module.

>>> import math
>>> math.fsum([2,3,4])

9.0

>>> math.fsum(range(1,4))

6.0

>>> math.fsum([0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01])

0.1

>>> sum([0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01])

0.0999999999999999999 #sum is less accurate than math.fsum