numpy-stubs: experimental typing stubs for NumPy

This repository exists for developing PEP 484 compatible typing annotations for NumPy.

It will be released as a separate "numpy-stubs" package on PyPI per PEP 561. This will let us iterate rapidly on experimental type annotations without coupling to NumPy's release cycle.

The plan (help wanted!):

1. Write basic type stubs for numpy.ndarray without dtypes or shapes.
2. Add support for dtypes in ndarray type-annotations.
   • This might be as simple as writing np.ndarray[np.float64], but will need a decision about appropriate syntax for shape typing to ensure that this is forwards compatible with typing shapes.
   • This will likely require minor changes to NumPy itself, e.g., to add ndarray.__class_getitem__ per PEP 560.
3. Add support for shapes in ndarray type-annotations.
   • This will first require defining a broader (Python wide) standard for typing array shapes, and likely entail writing a PEP.

Eventually, once development has stabilized, we expect to merge these type stubs into the main NumPy repository.