Message97793
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 ;-) |
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Date |
User |
Action |
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2010-01-14 22:37:42 | tim.peters | set | recipients:
+ tim.peters, mark.dickinson, DhaReaL |
2010-01-14 22:37:42 | tim.peters | set | messageid: <1263508662.41.0.908399474474.issue7704@psf.upfronthosting.co.za> |
2010-01-14 22:37:41 | tim.peters | link | issue7704 messages |
2010-01-14 22:37:40 | tim.peters | create | |
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