I want to use it for a currency exchange program. It's useful, then the user wouldn't have to round it himself/herself, and mistakes could be avoided.
Nathan Pinno --------------------------------------------------------------- Early to bed, Early to rise, Makes a man healthy, wealthy, and wise. --Benjamin Franklin ------------------------------------------------------------------- Languages I know: Python, English Languages I am learning: C++, Java, Javascript ----- Original Message ----- From: "Bob Gailer" <[EMAIL PROTECTED]> To: "Nathan Pinno" <[EMAIL PROTECTED]>; "Tutor mailing list" <tutor@python.org> Sent: Thursday, August 18, 2005 11:11 AM Subject: Re: [Tutor] Is there anyway to set how many numbers are used after the decimal in floating numbers? > At 10:31 AM 8/18/2005, Nathan Pinno wrote: >>Is there anyway to set how many numbers are used after the decimal in >>floating numbers? It would be nice if the answer could be rounded to 2 >>decimal spots, instead of the ten millionths spot. > > The simple answer is NO. Floating point numbers have a "fixed" number of > digits and an exponent to place the decimal point. You can control how > many digits are "displayed" using % formatting. > >>> 5./3 > 1.6666666666666667 > >>> '%6.3f' % (5./3) # notice this rounds and formats > ' 1.667' > > There are various other ways to accomplish your goals depending on what > they are. What are you using floating point numbers for? It is easy to get > into trouble with floating point arithmetic since (1) most decimal numbers > do not have an exact floating point representation, and (2) the limited > precision can caus cumulative errors. Example: > >>> i = 0.0 > >>> for j in range(10):i += j*.1 > >>> i > 4.5000000000000009 > > If you have Python 2.4 + the decimal module may give you what you need. > > Bob Gailer > 303 442 2625 home > 720 938 2625 cell > _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
