How do I distribute fonts with my python package?

Question

I have created a package called clearplot that wraps around matplotlib. I have also created a nice font that I want to distribute with my package. I consulted this section of the Python Packaging User guide, and determined that I should use the data_files keyword. I chose data_files instead of package_data since I need to install the font in a matplotlib directory that is outside of my package.

Here is my first, flawed, attempt at a setup.py file:

from distutils.core import setup
import os, sys
import matplotlib as mpl

#Find where matplotlib stores its True Type fonts
mpl_data_dir = os.path.dirname(mpl.matplotlib_fname())
mpl_ttf_dir = os.path.join(mpl_data_dir, 'fonts', 'ttf')

setup(
    ...(edited for brevity)...
    install_requires = ['matplotlib >= 1.4.0, !=1.4.3', 'numpy >= 1.6'],
    data_files = [
        (mpl_ttf_dir, ['./font_files/TeXGyreHeros-txfonts/TeXGyreHerosTXfonts-Regular.ttf']),
        (mpl_ttf_dir, ['./font_files/TeXGyreHeros-txfonts/TeXGyreHerosTXfonts-Italic.ttf'])]
)

#Try to delete matplotlib's fontList cache
mpl_cache_dir = mpl.get_cachedir()
mpl_cache_dir_ls = os.listdir(mpl_cache_dir)
if 'fontList.cache' in mpl_cache_dir_ls:
    fontList_path = os.path.join(mpl_cache_dir, 'fontList.cache')
    os.remove(fontList_path)

There are two issues with this setup.py:

1. I attempt to import matplotlib before setup() has a chance to install it. This is an obvious booboo, but I needed to know where mpl_ttf_dir was before I ran setup().
2. As mentioned here, wheel distributions do not support absolute paths for data_files. I didn't think this would be a problem because I thought I would just use a sdist distribution. (sdists do allow absolute paths.) Then I came to find out that pip 7.0 (and later) converts all packages to wheel distributions, even if the distribution was originally created as a sdist.

I was quite annoyed by issue #2, but, since then, I found out that absolute paths are bad because they do not work with virtualenv. Thus, I am now willing to change my approach, but what do I do?

The only idea I have is to distribute the font as package_data first and then move the font to the proper location afterwards using the os module. Is that a kosher method?

Answer 1

Thanks to @benjaoming's answer and this blog post, here is what I came up with:

from setuptools import setup
from setuptools.command.install import install
import warnings

#Set up the machinery to install custom fonts.  Subclass the setup tools install 
#class in order to run custom commands during installation.  
class move_ttf(install):
    def run(self):
        """
        Performs the usual install process and then copies the True Type fonts 
        that come with clearplot into matplotlib's True Type font directory, 
        and deletes the matplotlib fontList.cache 
        """
        #Perform the usual install process
        install.run(self)
        #Try to install custom fonts
        try:
            import os, shutil
            import matplotlib as mpl
            import clearplot as cp

            #Find where matplotlib stores its True Type fonts
            mpl_data_dir = os.path.dirname(mpl.matplotlib_fname())
            mpl_ttf_dir = os.path.join(mpl_data_dir, 'fonts', 'ttf')

            #Copy the font files to matplotlib's True Type font directory
            #(I originally tried to move the font files instead of copy them,
            #but it did not seem to work, so I gave up.)
            cp_ttf_dir = os.path.join(os.path.dirname(cp.__file__), 'true_type_fonts')
            for file_name in os.listdir(cp_ttf_dir):
                if file_name[-4:] == '.ttf':
                    old_path = os.path.join(cp_ttf_dir, file_name)
                    new_path = os.path.join(mpl_ttf_dir, file_name)
                    shutil.copyfile(old_path, new_path)
                    print "Copying " + old_path + " -> " + new_path

            #Try to delete matplotlib's fontList cache
            mpl_cache_dir = mpl.get_cachedir()
            mpl_cache_dir_ls = os.listdir(mpl_cache_dir)
            if 'fontList.cache' in mpl_cache_dir_ls:
                fontList_path = os.path.join(mpl_cache_dir, 'fontList.cache')
                os.remove(fontList_path)
                print "Deleted the matplotlib fontList.cache"
        except:
            warnings.warn("WARNING: An issue occured while installing the custom fonts for clearplot.")

setup(...
    #Specify the dependencies and versions
    install_requires = ['matplotlib >= 1.4.0, !=1.4.3', 'numpy >= 1.6'],
    #Specify any non-python files to be distributed with the package
    package_data = {'' : ['color_maps/*.csv', 'true_type_fonts/*.ttf']},
    #Specify the custom install class
    cmdclass={'install' : move_ttf}
)

This solves both problem #1 (it installs matplotlib before it imports it) and problem #2 (it works with wheels).