A RetroSearch Logo

Home - News ( United States | United Kingdom | Italy | Germany ) - Football scores

Search Query:

Showing content from http://mail.python.org/pipermail/python-dev/2010-March/098854.html below:

[Python-Dev] Why is nan != nan?

[Python-Dev] Why is nan != nan? [Python-Dev] Why is nan != nan?Alexander Belopolsky alexander.belopolsky at gmail.com
Wed Mar 24 23:36:49 CET 2010
On Wed, Mar 24, 2010 at 6:31 PM, Mark Dickinson <dickinsm at gmail.com> wrote:
..
> Neither is necessary, because Python doesn't actually use == as the
> equivalence relation for containment testing:  the actual equivalence
> relation is:  x equivalent to y iff id(x) == id(y) or x == y.  This
> restores the missing reflexivity (besides being a useful
> optimization).

No, it does not:

>>> float('nan') in [float('nan')]
False


It would if NaNs were always interned, but they are not.
More information about the Python-Dev mailing list

RetroSearch is an open source project built by @garambo | Open a GitHub Issue

Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo

HTML: 3.2 | Encoding: UTF-8 | Version: 0.7.4