For each directory, do:
# Fails because package not found, since the import
# is on a different directory ("package").
python test.py
cd package
python package/setup.py install --user
# Works, using the installed version.
cd ..
python test.py
# Cleanup
# http://stackoverflow.com/questions/402359/how-do-you-uninstall-a-python-package-that-was-installed-using-distutils/43650802#43650802
rm -rf files.txt
sudo python setup.py install --record files.txt
xargs sudo rm -rf < files.txt
rm -rf files.txt
# Fails again.
python test.py