# Contributing to `scoring-matrices`

For bug fixes or new features, please file an issue before submitting a
pull request. If the change isn't trivial, it may be best to wait for
feedback.

## Setting up a local repository

You can just clone the GitHub repository to a local folder and start working
from there:

```console
$ git clone https://github.com/althonos/scoring-matrices
```

## Running tests

Tests are written as usual Python unit tests with the `unittest` module of
the standard library. Running them requires the extension to be built
locally:

```console
$ python -m pip install -v -e . --no-build-isolation
$ python -m unittest scoring_matrices.tests -vv
```

## Coding guidelines

This project targets Python 3.7 or later.

Python objects should be typed; since it is not supported by Cython,
you must manually declare types in type stubs (`.pyi` files). In Python
files, you can add type annotations to function signatures (supported in
Python 3.5) and in variable assignments (supported only from Python
3.6 onward). 

### Interfacing with C/C++

When interfacing with C or C++, and in particular with pointers, use
assertions everywhere you assume the pointer to be non-NULL. Also consider
using assertions when accessing raw C arrays, if applicable.