[Numpy-discussion] Request for enhancement to numpy.random.shuffle

[Warren Weckesser]

On Sun, Oct 12, 2014 at 7:57 AM, Robert Kern <robert.kern at gmail.com> wrote:

> On Sat, Oct 11, 2014 at 11:51 PM, Warren Weckesser
> <warren.weckesser at gmail.com> wrote:
>
> > A small wart in this API is the meaning of
> >
> >   shuffle(a, independent=False, axis=None)
> >
> > It could be argued that the correct behavior is to leave the
> > array unchanged. (The current behavior can be interpreted as
> > shuffling a 1-d sequence of monolithic blobs; the axis argument
> > specifies which axis of the array corresponds to the
> > sequence index.  Then `axis=None` means the argument is
> > a single monolithic blob, so there is nothing to shuffle.)
> > Or an error could be raised.
> >
> > What do you think?
>
> It seems to me a perfectly good reason to have two methods instead of
> one. I can't imagine when I wouldn't be using a literal True or False
> for this, so it really should be two different methods.
>
>

I agree, and my first inclination was to propose a different method (and I
had the bikeshedding conversation with myself about the name: "disarrange",
"scramble", "disorder", "randomize", "ashuffle", some other variation of
the word "shuffle", ...), but I figured the first thing folks would say is
"Why not just add options to shuffle?"  So, choose your battles and all
that.

What do other folks think of making a separate method?



> That said, I would just make the axis=None behavior the same for both
> methods. axis=None does *not* mean "treat this like a single
> monolithic blob" in any of the axis=-having methods; it means "flatten
> the array and do the operation on the single flattened axis". I think
> the latter behavior is a reasonable interpretation of axis=None for
> both methods.
>


Sounds good to me.

Warren



>
> --
> Robert Kern
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