Decimal ROUND_HALF_EVEN Default

Tim Peters tim.peters at
Mon Jan 16 19:33:45 EST 2006

> I'm just curious as to why the default rounding in the decimal module is

Because it's the best (numerically "fairest") rounding method for most
people most of the time.

> All of the decimal arithmetic I do is rounded half up and I can't think of
> why one might use round half even.

Because you want better numeric results, or because your application
requires it.  "Half-even" is also called "banker's rounding" in the
United States, because it's required in many (but not all) banking

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