[Numpy-discussion] Splitting MaskedArray into a separate package

[Matti Picus]

MaskedArray is a strange but useful creature. This NEP proposes to 
distribute it as a separate package under the NumPy brand.

As I understand the process, a proposed NEP should be first discussed 
here to gauge general acceptance, then after that the details should be 
discussed on the pull request itself 
https://github.com/numpy/numpy/pull/11146.

Here is the motivation section from the NEP:

> MaskedArrays are a sub-class of the NumPy ``ndarray`` that adds
> masking capabilities, i.e. the ability to ignore or hide certain array
> values during computation.
>
> While historically convenient to distribute this class inside of NumPy,
> improved packaging has made it possible to distribute it separately
> without difficulty.
>
> Motivations for this move include:
>
>  * Focus: the NumPy package should strive to only include the
>    `ndarray` object, and the essential utilities needed to manipulate
>    such arrays.
>  * Complexity: the MaskedArray implementation is non-trivial, and imposes
>    a significant maintenance burden.
>  * Compatibility: MaskedArray objects, being subclasses of `ndarrays`,
>    often cause complications when being used with other packages.
>    Fixing these issues is outside the scope of NumPy development.
>
> This NEP proposes a deprecation pathway through which MaskedArrays
> would still be accessible to users, but no longer as part of the core
> package.

Any thoughts?

Matti and Stefan