code: def observation_input(ob_space, batch_size=None, name='Ob'):
      '''
      Create placeholder to feed observations into of the size appropriate to the observation space, and add input
      encoder of the appropriate type.
      '''
  
      placeholder = observation_placeholder(ob_space, batch_size, name)
      return placeholder, encode_observation(ob_space, placeholderf observation_input(ob_space, batch_size=None, name='Ob'):
      '''
      Create placeholder to feed observations into of the size appropriate to the observation space, and add input
      encoder of the appropriate type.
      '''
  
      placeholder = observation_placeholder(ob_space, batch_size, name)
      return placeholder, encode_observation(ob_space, placeholder)
docs: Create placeholder to feed observations into of the size appropriate to the observation space, and add input
      encoder of the appropriate type.