[Python-ideas] Way to check for floating point "closeness"?

Chris Barker chris.barker at noaa.gov
Mon Jan 12 18:02:17 CET 2015

Now that we're talking about floating point conveniences (math.nan,

What about putting an


(or close(), or...) in the math module.

AFAICT, in the standard library, there is only:


but it:

A) is buried in the unittest.TestCase class

B) is an assertion, so you can't use it as a general test (easily)

C) uses number of decimal digits or an absolute delta, but does not provide
a significant figures comparison, which is most likely what's wanted (and a
bit harder to write yourself)

numpy provides allclose() (and isclose() ), which is pretty much what I'm

Anyone else think this would be a good idea to add to the stdlib?



Christopher Barker, Ph.D.

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Chris.Barker at noaa.gov
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