Planning a Python Course for Beginners

[Python]

Marko Rauhamaa wrote:
> id() is actually an ideal return value of __hash__(). The only criterion
> is that the returned number should be different if the __eq__() is
> False. That is definitely true for id().

$ python
Python 2.7.13 (default, Jan 19 2017, 14:48:08)
[GCC 6.3.0 20170118] on linux2
Type "help", "copyright", "credits" or "license" for more information.
 >>> nan = float('NaN')
 >>> id(nan) == id(nan)
True
 >>> nan == nan
False
 >>>