Class _EmptyBinding

dm_control/mjcf/physics.py:403–418

The result of binding no `mjcf.Elements` to an `mjcf.Physics` instance.

class _EmptyBinding:
  """The result of binding no `mjcf.Elements` to an `mjcf.Physics` instance."""

  __slots__ = ('_arr',)

  def __init__(self):
    self._arr = np.empty((0))

  def __getattr__(self, name):
    return self._arr

  def __setattr__(self, name, value):
    if name in self.__slots__:
      super().__setattr__(name, value)
    else:
      raise ValueError('Cannot assign a value to an empty binding.')

_EMPTY_BINDING = _EmptyBinding()