Dick Moores wrote: > At 05:37 AM 9/7/2006, Andrei wrote: >> Dick Moores <rdm <at> rcblue.com> writes: >> >>> (2) Is my roundingN() function OK? Is there a better way to write it? >>> Will the line >>> >>> n = round(float(n)*(10**rounding))/(10**rounding) >> Using format strings is easier I think. "%.2f" % 2.34234 will give '2.34'. > > I had mistakenly believed that format strings could be used only in > print expressions! > > So now that I know better, I'm trying to write the beginnings of a > general setPrecision() function using format strings. However, it > appears that a variable cannot be used instead of the ".2" in > > "%.2f" % 2.234234
Yes, it can, just not the way you think - if you use a * for the precision, the value will be read from the provided parameters: In [1]: '%.*f' % (2, 2.234234) Out[1]: '2.23' In [2]: '%.*f' % (4, 2.234234) Out[2]: '2.2342' You can do this with the width parameter also which can be very useful when you have computed a field width: In [3]: '%*s' % (4, 'foo') Out[3]: ' foo' In [4]: '%*s' % (10, 'foo') Out[4]: ' foo' Kent _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
