My test implementation works for me on Python 2.7, see http://repl.it/9Wz

Notice especially the last few assertions, where normal datetime objects are on the LHS.

Regards,

Yawar

On 2015-01-29, at 2:04, Chris Barker <chris.barker@noaa.gov> wrote:

On Wed, Jan 28, 2015 at 6:55 PM, Yawar Amin <yawar.amin@gmail.com> wrote:

Cool, the comparison operator logic looks very similar to mine:

https://groups.google.com/d/msg/python-ideas/G3jeWoa6h14/ELpDLFu28QcJ

Did you get it to work both ways? i.e.

datetime.neg_inf < datetime.now()

and

datetime.now() > datetime.neg_inf

I had trouble with that, because the regular datetime doesn't know how to compare itself to a neg_inf object.
 

I believe the ideal design is the following type hierarchy:

    datetime_base
      datetime_neg_inf
      datetime_pos_inf
      datetime

But in the interests of pragmatism, I think this one can be made to
work:

    datetime
      datetime_neg_inf
      datetime_pos_inf

yup -- should work.

and you could add class methods to the datetime object, so you could do:

datetime.neg_inf()

and

datetime.pos_inf()

 

The

advantage to this is that we don't have to switch everything over to
using a new derived type--just use the normal datetime for the majority
of cases where we don't need inifinity dates.

And it could be a third part package, too. -- particularly good for backward compatibility.

-Chris

--

Christopher Barker, Ph.D.
Oceanographer

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