code: def python_versions(self):
          
          version_re = re.compile(r"""Programming Language \:\: """
                                  """Python \:\: \d\.\d""")
          return [c.split(' :: ')[-1] for c in self.classifiers
                  if version_re.match(c)]
docs: Returns a list of Python version strings that
          the package has listed in :attr:`yarg.Release.classifiers`.
  
              >>> package = yarg.get('yarg')
              >>> package.python_versions
              [u'2.6', u'2.7', u'3.3', u'3.4']