Python fsum function


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