Floating point problem

[Souvik Dutta]

I literally tried it!!! And it did not stop because I did not get any 1.0
rather I got 0.99999999999 But why does this happen. This is a simple math
which according to normal human logic should give perfect numbers which are
not endless. Then why does a computer behave so differently?

On Sat, 18 Apr, 2020, 7:02 pm DL Neil via Python-list, <
python-list at python.org> wrote:

> On 19/04/20 1:07 AM, Souvik Dutta wrote:
> > I have one question here. On using print(f"{c:.32f}") where c= 2/5
> instead
> > of getting 32 zeroes I got some random numbers. The exact thing is
> > 0.40000000000000002220446049250313
> > Why do I get this and not 32 zeroes?
>
> Approximating decimal numbers as binary values.
>
> Do NOT try this at home! How many lines will the following code display
> on-screen?
>
>  >>> v = 0.1
>  >>> while v != 1.0:
> ...     print(v)
> ...     v += 0.1
>
> As an exercise, try dividing 1.0 by 10.0 and then adding the result to
> itself ten times.
>
> Back in the ?good, old days, a Computer Science course would almost
> certainly involve some "Numerical Analysis", when such issues would be
> discussed. Not sure that many institutions offer such, these days...
> --
> Regards =dn
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>