dynamically include all files in folder with the package (and alternatively import each of those source files)

__init__.py

import os

_python_source_files = list( 
    filter(
        lambda basename: basename.endswith(".py") and 
            not basename.startswith('_'), 
                os.listdir( os.path.dirname(os.path.realpath(__file__)) ) 
    )
)

__all__ = [fn[:-3] for fn in _python_source_files]
del _python_source_files

# uncomment below if you want to import the submodules into the package namespace
# NOT sure if the blow works properly, but above works
# for mod in __all__: __import__(mod)