[Tutor] The '45' bug in round()

[Terry Carroll]

On Tue, 20 Mar 2007, Dick Moores wrote:

>  >>> print round(0.19965, 4)
> 0.1997
> 
> (which rounds up to an odd number, 7)

Now that's weird.  It should (I say) round to .1996; not because 6 is even
and 7 is not[1], but because 0.19965 is actually closer to 0.1996 than to
0.1997:

>>> 0.19965
0.19964999999999999


[1] The Python rounding rule is to round "away from zero," i.e., to round 
up for positive numbers and down (where "down" means "more negative") for 
negative numbers.