At 06:05 AM 8/11/2007, Kent Johnson wrote:
>Dick Moores wrote:
> > I was just about finished with a script that would tell the clerk how
> > to give the change to the customer, when I discovered that the above
> > script computes the wrong amount of change in certain situations. It
> > works fine if the customer tenders only bills and no change, but
> > that's not realistic. For example, if the cost is $1.78 the customer
> > may well tender $2.03 so he can get a quarter back rather than 2
> > dimes and 2 pennies. But the script in that case will compute change
> > of 24 cents! Try it out. I've put the same script on the web, but
> > deleted the line that I'd left in by mistake, "print coinCount".
>
>The problem is that
>int(100 * float("2.03"))
>is 202, not 203, because the float representation of 2.03 is actually
>2.0299999999999998.
>
>The same problem occurs if you enter 2.03 as the cost and 3.00 as the
>amount tendered; it computes change of $0.98.
>
>Use int(round(100 * float("2.03"))) to get the correct amount.
That did it. Thanks, Kent.
Here's the script that hands over change in the traditional way.
<http://www.rcblue.com/Misc/changeMakerKent_Traditional.py>
Is there a better way to handle the singulars and plurals?
Dick
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