npt-promote

Mypy plugin to add type promotions between NumPy and builtin data types.

The main use case for this plugin is to enable generic use of int and float type annotations with NumPy arrays, e.g.

import numpy as np
import numpy.typing as npt

x: npt.NDArray[float] = np.array((42.0))

Installation

Add npt-promote as a project dependency, e.g. as an optional dev requirement in pyproject.toml:

[project.optional-dependencies]
dev = ["mypy", "npt-promote"]

To use the plugin with mypy as a pre-commit hook, add the following to .pre-commit-config.yaml:

- repo: https://github.com/pre-commit/mirrors-mypy
  hooks:
  - id: mypy
    additional_dependencies: [
      "npt-promote"
    ]

To enable the plugin, it must be added to your project's mypy configuration file along with NumPy's mypy plugin. E.g. add the following to pyproject.toml:

[tool.mypy]
plugins = [
  'numpy.typing.mypy_plugin',
  'npt_promote',
]

To run the tests, execute:

pytest --mypy-only-local-stub