Development

Testing

To just test the module, install the package with test option and run the following command in the project root directory:

pytest

To perform the full test (e.g., linting and type checking), install with dev option and build the document before testing. Then, run the following command in the project root directory:

flake8
black --check .
isort --check .
docformatter --check .
doc8 .
mypy src
pytest

Caching

Image processing is computationally expensive. To enhance the performance, expensive functions that are called multiple times can be cached.

When caching methods of image classes (ReferenceBase, SubstrateBase, and CoatingLayerBase), remember that the data MUST be stored in the instance itself, not in external container, e.g., using functools.cache(). This is because external caching increases the reference count of the instance, preventing it from being garbage collected on time. Instances storing image consume large memory space, and will crash the program if they are keep being kept in external cache.

This also requires that attributes of these classes should not be mutated. Using @property is recommended to prevent accidental mutation.

__slots__

Image classes (ReferenceBase, SubstrateBase, and CoatingLayerBase) do not need to define object.__slots__.

Slots are useful when large number of objects simultaneously exist. This does not hold for core classes which are designed to be sequentially constructed and destroyed.