API/OP (Conv2DTranspose) error message enhancement (#23590)

* error message enhancement for Conv2DTranspose, test=develop

* fix error_message, test=develop

python/paddle/fluid/dygraph/nn.py

@@ -2458,6 +2458,10 @@ class Conv2DTranspose(layers.Layer):
             return dygraph_utils._append_activation_in_dygraph(
                 pre_act, act=self._act)
 
+        check_variable_and_dtype(input, 'input',
+                                 ['float16', 'float32', 'float64'],
+                                 "Conv2DTranspose")
+
         inputs = {'Input': [input], 'Filter': [self.weight]}
         attrs = {
             'output_size': self._output_size,

python/paddle/fluid/tests/unittests/test_layers.py

@@ -617,6 +617,28 @@ class TestLayer(LayerTest):
             self.assertTrue(
                 np.array_equal(conv2d1.bias.numpy(), conv2d2.bias.numpy()))
 
+        with self.static_graph():
+
+            # the input of Conv2DTranspose must be Variable.
+            def test_Variable():
+                images = np.ones([2, 3, 5, 5], dtype='float32')
+                conv2d = nn.Conv2DTranspose(
+                    num_channels=3, num_filters=3, filter_size=[2, 2])
+                conv2d_ret1 = conv2d(images)
+
+            self.assertRaises(TypeError, test_Variable)
+
+            # the input dtype of Conv2DTranspose must be float16 or float32 or float64
+            # float16 only can be set on GPU place
+            def test_type():
+                images = layers.data(
+                    name='pixel', shape=[3, 5, 5], dtype='int32')
+                conv2d = nn.Conv2DTranspose(
+                    num_channels=3, num_filters=3, filter_size=[2, 2])
+                conv2d_ret2 = conv2d(images)
+
+            self.assertRaises(TypeError, test_type)
+
     def test_bilinear_tensor_product(self):
         inp_np_x = np.array([[1, 2, 3]]).astype('float32')
         inp_np_y = np.array([[4, 5, 6]]).astype('float32')