code: def p_array_indices(self, p):
          '''array_indices : array_index
                           | array_index COMMA array_indices'''
          if len(p) == 2:
              p[0] = p[1],
          else:
              p[0] = (p[1],) + p[3f p_array_indices(self, p):
          '''array_indices : array_index
                           | array_index COMMA array_indices'''
          if len(p) == 2:
              p[0] = p[1],
          else:
              p[0] = (p[1],) + p[3]
docs: array_indices : array_index
                           | array_index COMMA array_indices