add __init__.py file

[Avery2]

This just adds an empty __init__.py file in the mastml directory. This is because python needs it to treat the mastml directory as a package.

From the python docs¹:

The __init__.py files are required to make Python treat directories containing the file as packages. This prevents directories with a common name, such as string, unintentionally hiding valid modules that occur later on the module search path. In the simplest case, __init__.py can just be an empty file, but it can also execute initialization code for the package or set the __all__ variable, described later.

Without it you get the following linting error when running things locally:

from mastml.mastml import Mastml
# Import "mastml.mastml" could not be resolved Pylancereport(MissingImports)

Footnotes

1. https://docs.python.org/3/tutorial/modules.html#packages ↩