Python Problem II

Question

Can any one explain why floating point calculations are so inaccurate?
This is because I discovered something:

I just add an float to an another float just like this:
print(1.2 - 1.0)
But instead of displaying 0.2, why output is 0.19999999999999996?

And situations are the same even I make it more specific, lets say:
print(1.200000 - 1.000000)
Why 0.19999999999999996 is still the output?

Thanks for any response that you make.

Answer 1

No. That's not a bug. It's nature of binary floating point numbers. So that's why it is not advisable to relay of floating point numbers in large codes because that messy thing.

Edit:
James Clark I. Vinarao
This will explain in more details, take a look
https://docs.python.org/3/tutorial/floatingpoint.html#tut-fp-issues)

Answer 2

That's depends on compiler internals.. see some other similar discussions. May help you...
https://www.sololearn.com/discuss/2080262/?ref=app
https://www.sololearn.com/discuss/2149084/?ref=app
https://www.sololearn.com/discuss/1733175/?ref=app
https://www.sololearn.com/discuss/1001890/?ref=app
https://www.sololearn.com/discuss/796595/?ref=app

Answer 3

When python stores floating-point numbers it uses binary instead of the way we do it which is Decimal

Answer 4

decimal is when we get to ten it’s two digit, but binary is when u count to two it gets to ten like this: 1,10,11,20,21