title: Any python function to get "data_files" root directory?
body: <p>This should be a very common question for developers who used "setup.py" to build installation packages and it should be asked before but I couldn't find the proper answer anywhere.</p>
  
  <p>In setup.py</p>
  
  <pre><code>from distutils.core import setup
  setup(
      ....,
      ....,
      data_files=[('MyApp/CBV', ['myapp/data/CBV/training.cbv', 'myapp/data/CBV/test.cbv'])],
      ....,
      ....,
      )
  </code></pre>
  
  <p>Result of sudo python setup.py install</p>
  
  <pre><code>running install
  running build
  running build_py
  running build_scripts
  running install_lib
  running install_scripts
  changing mode of /usr/local/bin/MyApp_trainer to 755
  changing mode of /usr/local/bin/MyApp_reference_updater to 755
  changing mode of /usr/local/bin/MyApp_predictor to 755
  changing mode of /usr/local/bin/reference_updater to 755
  running install_data
  creating /usr/local/MyApp/CBV
  copying MyApp/data/CBV/training.cbv -&gt; /usr/local/MyApp/CBV
  copying MyApp/data/CBV/test.cbv -&gt; /usr/local/MyApp/CBV
  running install_egg_info
  Removing /usr/local/lib/python2.7/dist-packages/MyApp-0.1.0.egg-info
  Writing /usr/local/lib/python2.7/dist-packages/MyApp-0.1.0.egg-info
  </code></pre>
  
  <p>From the observation using the result above, "/usr/local" is the "data_files" root directory. Other than hardcoding, are there any Python functions that can give me this "data_files" root directory?</p>