text: import unittest
  
  import paddle.v2.fluid.core as core
  
  from paddle.v2.fluid.framework import Program, default_startup_program
  
  main_program = default_startup_program()
  
  
  class TestOperator(unittest.TestCase):
      def test_error_type(self):
          block = main_program.create_block()
          try:
              block.append_op()
              self.assertFail()
          except ValueError as v_err:
              self.assertEqual(
                  v_err.message,
                  "`type` to initilized an Operator can not be None.")
          try:
              block.append_op(type="no_such_op")
              self.assertFail()
          except ValueError as a_err:
              self.assertEqual(a_err.message,
                               "Operator \"no_such_op\" has not been registered.")
  
      def test_op_desc_creation(self):
          program = Program()
          block = program.current_block()
          mul_x = block.create_var(
              dtype="float32", shape=[5, 10], lod_level=0, name="mul.x")
          mul_y = block.create_var(
              dtype="float32", shape=[10, 8], lod_level=0, name="mul.y")
          mul_out = block.create_var(
              dtype="float32", shape=[5, 8], lod_level=0, name="mul.out")
          mul_op = block.append_op(
              type="mul",
              inputs={"X": [mul_x],
                      "Y": mul_y},
              outputs={"Out": [mul_out]},
              attrs={"x_num_col_dims": 1})
  
          self.assertNotEqual(str(mul_op), "")
          self.assertEqual(mul_op.type, "mul")
          self.assertEqual(mul_op.input_names, ["X", "Y"])
          self.assertEqual(mul_op.input("X"), ["mul.x"])
          self.assertEqual(mul_op.input("Y"), ["mul.y"])
          self.assertEqual(mul_op.output_names, ["Out"])
          self.assertEqual(mul_op.output("Out"), ["mul.out"])
          self.assertEqual(
              set(mul_op.attr_names), set(["x_num_col_dims", "y_num_col_dims"]))
          self.assertEqual(mul_op.has_attr("x_num_col_dims"), True)
          self.assertEqual(mul_op.attr_type("x_num_col_dims"), core.AttrType.INT)
          self.assertEqual(mul_op.attr("x_num_col_dims"), 1)
          self.assertEqual(mul_op.has_attr("y_num_col_dims"), True)
          self.assertEqual(mul_op.attr_type("y_num_col_dims"), core.AttrType.INT)
          self.assertEqual(mul_op.attr("y_num_col_dims"), 1)
          self.assertEqual(mul_op.idx, 0)
          self.assertEqual(mul_out.op, mul_op)
  
      def test_mult_input(self):
          program = Program()
          block = program.current_block()
          sum_x1 = block.create_var(
              dtype="int", shape=[3, 4], lod_level=0, name="sum.x1")
          sum_x2 = block.create_var(
              dtype="int", shape=[3, 4], lod_level=0, name="sum.x2")
          sum_x3 = block.create_var(
              dtype="int", shape=[3, 4], lod_level=0, name="sum.x3")
          sum_out = block.create_var(
              dtype="int", shape=[3, 4], lod_level=0, name="sum.out")
          sum_op = block.append_op(
              type="sum",
              inputs={"X": [sum_x1, sum_x2, sum_x3]},
              outputs={"Out": sum_out})
          self.assertEqual(sum_op.type, "sum")
          self.assertEqual(sum_op.input_names, ["X"])
          self.assertEqual(sum_op.input("X"), ["sum.x1", "sum.x2", "sum.x3"])
          self.assertEqual(sum_op.output_names, ["Out"])
          self.assertEqual(sum_op.output("Out"), ["sum.out"])
          self.assertEqual(sum_op.idx, 0)
          self.assertEqual(sum_out.op, sum_op)
  
  
  if __name__ == '__main__':
      unittest.main()
  