[Tutor] Re: integers and float

[Derrick 'dman' Hudson]

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On Fri, Jul 19, 2002 at 09:14:46AM -0700, MIG wrote:
| I've got a question with float and $.

No. No. No. No. No.

Never never ever use floating point for handling money.  Always use
integers or fixed point.

If you want a demonstration of why, try this :

>>> print "%.40f" % 0.1
0.1000000000000000055511151231257827021182

For another example that doesn't involve binary, use a pencil and
paper and rewrite the expresion
    1/3
in decimal.  No, don't approximate it.  Write it *exactly*.  Ok,
nevermind I don't want to kill you.  (you can't, it's a "repeating
decimal")

If you want to learn more about binary floating point than you ever
cared, just ask Tim Peters :-).  (he's a guru with that stuff)

-D

--=20
The wise in heart are called discerning,
and pleasant words promote instruction.
        Proverbs 16:21
=20
http://dman.ddts.net/~dman/

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