fix output_padding in conv (#33429)

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)
@@ -163,7 +163,7 @@ 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:
+        if self._output_padding != 0:
             main_str += ', output_padding={_output_padding}'
         if self._dilation != [1] * len(self._dilation):
             main_str += ', dilation={_dilation}'
@@ -502,7 +502,7 @@ 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,
@@ -810,7 +810,7 @@ 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
 
@@ -1139,7 +1139,7 @@ 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