Recursively gets attributes inside `module` as specified by `path`.

def _recursive_getattr(module, path):
  """Recursively gets attributes inside `module` as specified by `path`."""
  if "." not in path:
    return getattr(module, path)
  else:
    first, rest = path.split(".", 1)
    return _recursive_getattr(getattr(module, first), rest)