Upgrade string literals to raw string [part 2](#29217)

python/paddle/fluid/contrib/optimizer.py

@@ -24,7 +24,7 @@ __all__ = ['Momentum']
 
 
 class Momentum(Optimizer):
-    """
+    r"""
 
     Simple Momentum optimizer with velocity state
 

python/paddle/fluid/dygraph/nn.py

@@ -2979,7 +2979,7 @@ class GroupNorm(layers.Layer):
 
 
 class SpectralNorm(layers.Layer):
-    """
+    r"""
     This interface is used to construct a callable object of the ``SpectralNorm`` class.
     For more details, refer to code examples. It implements the function of the Spectral Normalization Layer.
     This layer calculates the spectral normalization value of weight parameters of

python/paddle/nn/functional/loss.py

@@ -1123,7 +1123,7 @@ def cross_entropy(input,
                   soft_label=False,
                   axis=-1,
                   name=None):
-    """
+    r"""
     This operator implements the cross entropy loss function with softmax. This function 
     combines the calculation of the softmax operation and the cross entropy loss function 
     to provide a more numerically stable gradient.

python/paddle/nn/layer/loss.py

@@ -141,7 +141,7 @@ class BCEWithLogitsLoss(fluid.dygraph.Layer):
 
 
 class CrossEntropyLoss(fluid.dygraph.Layer):
-    """
+    r"""
     This operator implements the cross entropy loss function with softmax. This function 
     combines the calculation of the softmax operation and the cross entropy loss function 
     to provide a more numerically stable gradient.
@@ -623,7 +623,7 @@ class BCELoss(fluid.dygraph.Layer):
 
 
 class NLLLoss(fluid.dygraph.Layer):
-    """
+    r"""
 	:alias_main: paddle.nn.NLLLoss
 	:alias: paddle.nn.NLLLoss,paddle.nn.layer.NLLLoss,paddle.nn.layer.loss.NLLLoss
 

python/paddle/optimizer/lamb.py

@@ -21,7 +21,7 @@ __all__ = ["Lamb"]
 
 
 class Lamb(Optimizer):
-    """
+    r"""
     LAMB (Layer-wise Adaptive Moments optimizer for Batching training) Optimizer.
 
     LAMB Optimizer is designed to scale up the batch size of training without losing

python/paddle/vision/ops.py

@@ -34,7 +34,7 @@ def yolo_loss(x,
               use_label_smooth=True,
               name=None,
               scale_x_y=1.):
-    """
+    r"""
 
     This operator generates YOLOv3 loss based on given predict result and ground
     truth boxes.
@@ -242,7 +242,7 @@ def yolo_box(x,
              clip_bbox=True,
              name=None,
              scale_x_y=1.):
-    """
+    r"""
 
     This operator generates YOLO detection boxes from output of YOLOv3 network.