The code needed to keep track of all the available moves for a player is as follows:

def get_all_available_moves(self, color):
  result = []
  for position in self.keys():
    piece = self.get_piece_at(position)
    if piece and piece.color == color:
       moves = piece.moves_available(position)
       if moves:
         result.extend(moves)
  return result

The description of the code is as follows:

• We have already coded the moves_available method in the previous iteration
• The preceding method simply iterates through every item in the dictionary and appends the moves_available result for every chess piece of a given color in a list named result