[Python-Dev] PEP 450 adding statistics module

[Eric V. Smith]

On 08/15/2013 01:58 PM, Mark Dickinson wrote:
> On Thu, Aug 15, 2013 at 2:08 PM, Steven D'Aprano <steve at pearwood.info
> <mailto:steve at pearwood.info>> wrote:
> 
> 
>     - Each scheme ended up needing to be a separate function, for ease
>     of both implementation and testing. So I had four private median
>     functions, which I put inside a class to act as namespace and avoid
>     polluting the main namespace. Then I needed a "master function" to
>     select which of the methods should be called, with all the
>     additional testing and documentation that entailed.
> 
> 
> That's just an implementation issue, though, and sounds like a minor
> inconvenience to the implementor rather than anything serious;  I don't
> think that that should dictate the API that's used.
> 
>     - The API doesn't really feel very Pythonic to me. For example, we
>     write:
> 
> 
> And I guess this is subjective:  conversely, the API you're proposing
> doesn't feel Pythonic to me. :-)  I'd like the hear the opinion of other
> python-dev readers.

I agree with Mark: the proposed median, median.low, etc., doesn't feel
right. Is there any example of doing this in the stdlib? I suggest just
median(), median_low(), etc.

If we do end up keeping it, simpler than the callable singleton is:

>>> def median(): return 'median'
...
>>> def _median_low(): return 'median.low'
...
>>> median.low = _median_low
>>> del _median_low
>>> median()
'median'
>>> median.low()
'median.low'

Eric.