Tim Peters <tim.pet...@gmail.com> added the comment: You can use the comparison, provided you understand what it does, and that it does NOT do what you hoped it would do. Here:
>>> 1.6 - 1.0 0.60000000000000009 That shows quite clearly that subtracting 1 from the binary approximation to 1.6 does not leave exactly 0.6. If you need that to happen, use the decimal module (which, in return for being slower, emulates decimal floating-point arithmetic). Your other case (8.6-8.0) does NOT equal (decimal) 0.6 exactly either, but fools you into thinking it's working the way you hope it works because the result is a little /less/ than 0.6: >>> 8.6 - 8.0 0.59999999999999964 Do read the tutorial appendix Mark invited you to read. If you don't, you're going to remain hopelessly confused ;-) ---------- nosy: +tim_one _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue7704> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
