To run YAPF on all of YAPF:

$ PYTHONPATH=$PWD/yapf python -m yapf -i -r .

To run YAPF on just the files changed in the current git branch:

$ PYTHONPATH=$PWD/yapf python -m yapf -i $(git diff --name-only @{upstream})

• Run tests: python setup.py test [don't forget to run with Python 2.7 and 3.6]
• Bump version in yapf/__init__.py
• Build source distribution: python setup.py sdist
• Check it looks OK, install it onto a virtualenv, run tests, run yapf as a tool
• Build release: python setup.py sdist bdist_wheel
• Push to PyPI: twine upload dist/*
• Test in a clean virtualenv that 'pip install yapf' works with the new version
• Commit the version bump; add tag with git tag v<VERSION_NUM>; git push --tags

TODO: discuss how to use tox to make virtualenv testing easier.