title: Import a variable from setup.py from an external script
body: <p>I have a setup.py file like this (not in pwd, not in Python path, a random file somewhere):</p>
  
  <pre><code>import ext_modules
  
  config = {
      'name': 'mesos.executor',
      'version': '1.4.1',
      'description': 'Mesos native executor driver implementation',
      'author': 'Apache Mesos',
      'author_email': 'dev@mesos.apache.org',
      'url': 'http://pypi.python.org/pypi/mesos.executor',
      'namespace_packages': [ 'mesos' ],
      'packages': [ 'mesos', 'mesos.executor' ],
      'package_dir': { '': 'src' },
      'install_requires': [ 'mesos.interface == 1.4.1' ],
      'license': 'Apache 2.0',
      'keywords': 'mesos',
      'classifiers': [ ],
      'ext_modules': [ ext_modules.executor_module ]
  }
  
  from setuptools import setup
  setup(**config)
  </code></pre>
  
  <p>And from an external (Python) script I'd like to import config["install_requires"]. I'm looking for the most minimalist way of doing this as it's intended to be run from other scripts that might even not be Python.</p>
  
  <p>A Python one-liner would be awesome.</p>