Vedran: you are quoting von Neumann out of context, he was talking about generating random numbers, not rounding, and in the seven decades since he made his famous witticism, we of course know that there is absolutely nothing wrong with generating random numbers via arithmetical methods so long as you do it correctly :-)

I have read your comments in the linked Stackoverflow answer, and I don't agree that we shouldn't be rounding binary floats. I do, however, agree with your comment here that we ought to add a rounding mode to the built-in round function, that would be a much better idea than adding a multitude of individual rounding functions.

I proposed this idea some time ago:

https://mail.python.org/archives/list/python-dev@python.org/message/DVS3XSAKW37NDD37BE3IOCKRBRV3Y5A6/