Python arithmetic with small numbers

Question

I am getting the following unexpected result when I do arithmetic with small numbers in Python:

>>> sys.float_info
sys.float_info(max=1.797693134862         


        

Answer 1

you can handle those. note that

>>> 1.e-17 == 0
False

and

>>> 1.e-17 + 1.e-18
1.1e-17

you simply cannot handle 1-1e-17, because the mantissa won't fit in the finite precision