[EMAIL PROTECTED] wrote: > how about the discrepancy between > > >>> print 1.2345 > > 1.2345 > > >>> print "%10.3f" % 1.2345 # seems like a bug > > 1.234 > > the first one, print knows enough to recognize and print it as 1.2345. > however, in the second line, when it is round off, it doesn't know it > is 1.2345 any more.
I think maybe this is the reason: the first one, print will print it out with a rounding to the 11th decimal point, therefore hiding any floating point imperfection. however, in the second one, print will not first round it off to the 11th decimal point with a subsequent rounding off to the 3rd decimal point. In that case, the floating point imperfection is manifested. (by thinking it is 1.2344999999999999) a question is: since print can nicely hide and smooth out the floating point imperfection, and probably most people prefer it that way, how come the implementation of print "%10.3f" doesn't also do that -- eliminating the imperfection first, and then print it out accordingly. I think one argument is the loss of precision, but we only print it, rather than modify the number or the variable itself... hm... say, if a bank uses python to print out the "change that should be returned to the customer" using print "%20.2f", then there will be a cent missing here and there... why not smooth out that imperfection and return that penny to the customer? (not that they really care). -- http://mail.python.org/mailman/listinfo/python-list
