fix output_padding in conv (#33585)

* fix output padding conv

* add repr unittest for conv

python/paddle/fluid/tests/unittests/test_conv2d_transpose_op.py

@@ -18,6 +18,7 @@ import unittest
 import numpy as np
 
 import paddle
+import paddle.nn as nn
 paddle.enable_static()
 import paddle.fluid.core as core
 import paddle.fluid as fluid
@@ -898,5 +899,17 @@ class TestConv2DTransposeOpException(unittest.TestCase):
         self.assertRaises(ValueError, attr_padding_with_data_format)
 
 
+class TestConv2DTransposeRepr(unittest.TestCase):
+    def test_case(self):
+        paddle.disable_static()
+        x_var = paddle.uniform((2, 4, 8, 8), dtype='float32', min=-1., max=1.)
+        conv = nn.Conv2DTranspose(4, 6, (3, 3), output_padding=1, stride=2)
+        print(conv)
+        y_var = conv(x_var)
+        y_np = y_var.numpy()
+        self.assertIsNotNone(y_np)
+        paddle.enable_static()
+
+
 if __name__ == '__main__':
     unittest.main()

python/paddle/nn/layer/conv.py

@@ -98,7 +98,7 @@ class _ConvNd(layers.Layer):
                                                   'kernel_size')
         self._padding = padding
         self._padding_mode = padding_mode
-        self._output_padding = output_padding
+        self.output_padding = output_padding
         if dims != 1:
             self._updated_padding, self._padding_algorithm = _update_padding_nd(
                 padding, channel_last, dims)
@@ -163,8 +163,8 @@ class _ConvNd(layers.Layer):
             main_str += ', padding={_padding}'
         if self._padding_mode is not 'zeros':
             main_str += ', padding_mode={_padding_mode}'
-        if self._output_padding != 0:
-            main_str += ', output_padding={_output_padding}'
+        if self.output_padding != 0:
+            main_str += ', output_padding={output_padding}'
         if self._dilation != [1] * len(self._dilation):
             main_str += ', dilation={_dilation}'
         if self._groups != 1:
@@ -508,7 +508,7 @@ class Conv1DTranspose(_ConvNd):
             self.weight,
             bias=self.bias,
             output_size=output_size,
-            output_padding=self._output_padding,
+            output_padding=self.output_padding,
             padding=self._padding,
             stride=self._stride,
             dilation=self._dilation,
@@ -824,7 +824,7 @@ class Conv2DTranspose(_ConvNd):
 
     def forward(self, x, output_size=None):
         if output_size is None:
-            output_padding = self._output_padding
+            output_padding = self.output_padding
         else:
             output_padding = 0
 
@@ -1161,7 +1161,7 @@ class Conv3DTranspose(_ConvNd):
 
     def forward(self, x, output_size=None):
         if output_size is None:
-            output_padding = self._output_padding
+            output_padding = self.output_padding
         else:
             output_padding = 0