Numpy Typehint with nptyping and Array in PyCharm

Question

I try to use numpy with nptyping 's Array to do my typehinting.

I tried the following:

enemy_hand: Array[float, 48] = np.zeros(48)

I get an typerror:

Expected Type 'Array[float, Any]', got 'ndarray' instead

as far as I understand from this: https://pypi.org/project/nptyping/ thats how it should look.

Answer 1

nptyping is currently useless for static analysis. Quoting a post by the library's developer on its issue tracker,

mypy is just not supported by nptyping (yet)

I wouldn't put much hope in that "yet". NumPy's dtype and shape handling is very hard to fit into the typing / mypy static type model, and nptyping 's own design decisions are a poor fit for NumPy itself. For example, it doesn't look like the dev ever considered arrays that aren't 2D, so Array[str, 3] represents a 2D array with 3 rows and unspecified columns instead of a 3-element 1D array. All the implementation is in terms of rows and columns, too.

As far as I can tell, the only real functionality nptyping has is isinstance checks, and even that's buggy.