title: pkg_resources DeprecationWarning for use of '..' in resource path
body: <p>In a Python package I have a data file which is nested 'above' a file which requires it. e.g.</p>
  
  <pre><code>package
    data
      data.csv
    utils
      util.py
  </code></pre>
  
  <p>In util.py I obtain the file as a stream using pkg_resources; this allows the code to be run from source and when installed as a package.</p>
  
  <pre><code>    data_stream = pkg_resources.resource_stream(
          __name__, os.path.join("..", "data", "data.csv")
      )
  </code></pre>
  
  <p>This works fine, and allows the data file to be retrieved as expected.</p>
  
  <p>However, when I run tests which use the code in util.py, a Deprecationwarning is revealed, stating "DeprecationWarning: Use of .. or absolute path in a resource path is not allowed and will raise exceptions in a future release."</p>
  
  <p>But I'm not sure what the correct way to approach this is?</p>