[Python-Dev] Deprecating float.is_integer() (original) (raw)

Guido van Rossum guido at python.org
Wed Mar 21 14:59:47 EDT 2018

On Wed, Mar 21, 2018 at 11:14 AM, David Mertz <mertz at gnosis.cx> wrote:

I've been using and teaching python for close to 20 years and I never noticed that x.isinteger() exists until this thread. I would say the "one obvious way" is less than obvious.

On the other hand, x == int(x) is genuinely obvious... and it immediately suggests the probably better math.isclose(x, int(x)) that is what you usually mean.

We can argue about this forever, but I don't think I would have come up with that either when asked "how to test a float for being a whole number". I would probably have tried "x%1 == 0" which is terrible. I like to have an API that doesn't have the pitfalls of any of the "obvious" solutions that numerically naive people would come up with, and x.is_integer() is it. Let's keep it.

-- --Guido van Rossum (python.org/~guido) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.python.org/pipermail/python-dev/attachments/20180321/eaa50c00/attachment.html>

More information about the Python-Dev mailing list