code: def processor_coordinates_to_pnum(mesh_shape, coord):
    
    ret = 0
    multiplier = 1
    for c, d in zip(coord[::-1], mesh_shape.to_integer_list[::-1]):
      ret += multiplier * c
      multiplier *= d
    return ret
docs: Inverse of pnum_to_processor_coordinates.
  
    Args:
      mesh_shape: a Shape
      coord: a list of integers with length len(mesh_shape)
  
    Returns:
      an integer less than len(mesh_shape)