For non-python files to be included in an installation, they must be within one of the installed package directories. If you specify non-python files outside of your package directories in MANIFEST.in, they will be included in your distribution, but they will not be installed. The "documented" ways of installing arbitrary files outside of your package directories do not work reliably (as everyone has noticed by now).
The above answer from Julian Mann copies the files to your package directory in the build directory, so it does work, but not if you are installing in editable/develop mode (pip install -e or python setup.py develop). Based on this answer to a related question (and Julian's answer), below is an example that copies files to your installed package location either way after all the other install/develop tasks are done. The assumption here is that files file1 and file2 in your root-level data directory will be copied to your installed package directory (my_package), and that they will be accessible from python modules in your package using os.path.join(os.path.dirname(__file__), 'file1'), etc.
Remember to also do the MANIFEST.in stuff described above so that these files are also included in your distribution. Why setuptools would include files in your distribution and then silently never install them, is beyond my ken. Though installing them outside of your package directory is probably even more dubious.
import os
from setuptools import setup
from setuptools.command.develop import develop
from setuptools.command.install import install
from shutil import copyfile
HERE = os.path.abspath(os.path.dirname(__file__))
NAME = 'my_package'
def copy_files (target_path):
source_path = os.path.join(HERE, 'data')
for fn in ["file1", "file2"]:
copyfile(os.path.join(source_path, fn), os.path.join(target_path,fn))
class PostDevelopCommand(develop):
"""Post-installation for development mode."""
def run(self):
develop.run(self)
copy_files (os.path.abspath(NAME))
class PostInstallCommand(install):
"""Post-installation for installation mode."""
def run(self):
install.run(self)
copy_files (os.path.abspath(os.path.join(self.install_lib, NAME)))
setup(
name=NAME,
cmdclass={
'develop': PostDevelopCommand,
'install': PostInstallCommand,
},
version='0.1.0',
packages=[NAME],
include_package_data=True,
setup_requires=['setuptools_scm'],
)