Python Fraction Isuue

Question

I noticed that (n*3) * 0.1, where n = 0.25 to 2 results highly accurate fraction values, like 0.0750000001 or 0.3000000004.

However, when n = 3 i.e. 9 * 0.1 gives a proper 0.9!

Why this sort of discrepancy?

Answer 1

https://docs.python.org/3/tutorial/floatingpoint.html

Answer 2

check this. This is floating point error.

https://www.sololearn.com/discuss/1012768/?ref=app

https://stackoverflow.com/questions/19473770/how-to-avoid-floating-point-errors

Answer 3

As a note, if you want to work with real fractions, you can use the fractions module.

from fractions import Fraction
print(Fraction(1,2) + Fraction(1,3))
# 5/6