runtime-generics 1.0.3

Reuse type arguments explicitly passed at runtime to a generic class before instantiating.

runtime_generics 1.0.3

Highly into type-safe Python code?

runtime_generics is a niche Python library that allows you to reuse type arguments explicitly passed at runtime to generic classes before instantiation.

Simple example

3.12+ (PEP 695 syntax):

from runtime_generics import get_arg, runtime_generic

@runtime_generic
class MyGeneric[T]:
    type_argument: type[T]

    def __init__(self) -> None:
        self.type_argument = get_arg(self)

my_generic = MyGeneric[int]()
assert my_generic.type_argument is int

3.8+:

from __future__ import annotations

from typing import Generic, TypeVar
from runtime_generics import get_arg, runtime_generic

T = TypeVar("T")

@runtime_generic
class MyGeneric(Generic[T]):
    type_argument: type[T]

    def __init__(self) -> None:
        self.type_argument = get_arg(self)

my_generic = MyGeneric[int]()
assert my_generic.type_argument is int

Installation

For users 💻

pip install runtime-generics

For developers ❤️

Note: If you use Windows, it is highly recommended to complete the installation in the way presented below through WSL2.

First, install Poetry.
Poetry is an amazing tool for managing dependencies & virtual environments, building packages and publishing them.

curl -sSL https://install.python-poetry.org | python3 -

_{This way of installing Poetry on Linux is valid as of 2023-10-27.
If you encounter any problems, refer to the official documentation for the most up-to-date installation instructions.}

Be sure to have Python 3.8 installed—if you use pyenv, simply run:

pyenv install 3.8

Then, run:

git clone https://github.com/bswck/runtime_generics && cd runtime_generics && ./install && poetry shell

Legal info

© Copyright by bswck. This software is licensed under the MIT License.