pip tries to install package in the wrong location

Question

I have just created a Python package and uploaded it to PyPi (goosempl). Installing the package locally works:

$ python3 setup.py install

(It installs in usr/local/lib/python3.6/site-packages).

However installing it from PyPi gives a weird error:

$ pip3 install goosempl

...
PermissionError: [Errno 13] Permission denied: '/usr/local/goosempl' 

For some reason pip tries to install in the wrong location?!?

---

Here is the setup.py (stripped down a bit, it still causes the error):

import atexit
from setuptools import setup

__version__ = '0.1.0'

setup(
    name              = 'goosempl',
    version           = __version__,
    author            = 'Tom de Geus',
    author_email      = '[e-mail]',
    url               = 'https://github.com/tdegeus/GooseMPL',
    keywords          = 'matplotlib style',
    description       = 'Style and extension functions for matplotlib',
    long_description  = '',
    license           = 'MIT',
    install_requires  = ['matplotlib>=2.0.0'],
    packages          = ['goosempl'],
    data_files        = [('goosempl/stylelib',[
        'goosempl/stylelib/goose.mplstyle'
    ])],
)

I have uploaded it to PyPi using:

$ python3 setup.py sdist
$ python3 setup.py bdist_wheel --universal
$ twine upload dist/*

(My guess in that the problem is caused by the data_files)

Answer 1

With the help of @NilsWerner:

The problem was in data_files. I have changed this with package_data (which has a slightly different syntax):

package_data = {'goosempl/stylelib':[
    'goosempl/stylelib/goose.mplstyle'
]}, 

This results in the desired behavior.

Following the comments, one could also include these files in MANIFEST.in.