How do you add additional files to a wheel?

Question

How do control what files are included in a wheel? It appears MANIFEST.in isn\'t used by python setup.py bdist_wheel.

UPDATE

Answer 1

I had config/ directory with JSON files in it, which I needed to add to the wheel package. So, I've added these lines to MANIFEST.in:

recursive-include config/ *.json

The following directive to setup.py:

setup(
 ...
 include_package_data=True,
)

And nothing worked. Until I've created an empty file called __init__.py inside config/ directory.

(Python 3.6.7, wheel 3.6.7, setuptools 39.0.1)