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 bool, 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

Dependencies:

• mypy
• NumPy

Install it with:

python -m pip install npt-promote

Alternatively, add npt-promote as a project dependency wherever mypy is used, e.g. as an optional dev requirement in pyproject.toml:

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

Usage

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',
]

pre-commit

To use the plugin with mypy as a pre-commit hook, it must be added as a dependency, e.g. add the following to .pre-commit-config.yaml:

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

Testing

First, install npt-promote with dev requirements:

python -m pip install npt-promote[dev]

To run the tests, execute:

pytest