[Python-Dev] Return type of round, floor, and ceil in 2.6 (original) (raw)

Daniel Stutzbach daniel at stutzbachenterprises.com
Sun Jan 6 02:22:20 CET 2008

On Jan 4, 2008 1:31 PM, Tim Peters <tim.peters at gmail.com> wrote:

Curiously, round-to-nearest can be unboundedly more expensive to implement in some obscure contexts when floats can have very large exponents (as they can in Python's "decimal" module -- this is why the proposed decimal standard allows operations like "remainder-near" to fail if applied to inputs that are "too far apart":

Just to be clear, this problem doesn't come up in round(), right?

Because in round(), you just test the evenness of the last digit computed. There is never a need to compute extra digits just to perform the test.

-- Daniel Stutzbach, Ph.D. President, Stutzbach Enterprises LLC

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