code: def infer_paths(output_dir, **subdirs):
    
    directories = {}
    for name, path in six.iteritems(subdirs):
      directories[name] = path if path else os.path.join(output_dir, name)
    directories["output_dir"] = output_dir
    return directories
docs: Infers standard paths to policy and model directories.
  
    Example:
      >>> infer_paths("/some/output/dir/", policy="", model="custom/path")
      {"policy": "/some/output/dir/policy", "model": "custom/path",
      "output_dir":"/some/output/dir/"}
  
    Args:
      output_dir: output directory.
      **subdirs: sub-directories.
  
    Returns:
      a dictionary with the directories.