code: def get_subpackages_names(dir_):
      
  
      def is_package(d):
          d = os.path.join(dir_, d)
          return os.path.isdir(d) and glob.glob(os.path.join(d, '__init__.py*'))
  
      ret = list(filter(is_package, os.listdir(dir_)))
      ret.sort()
      return ret
docs: Figures out the names of the subpackages of a package
  
      Args:
          dir_: (str) path to package directory
  
      Source: http://stackoverflow.com/questions/832004/python-finding-all-packages-inside-a-package