Fix wrong operator "is" in string comparisons

tensorlayerx/backend/ops/paddle_nn.py

@@ -496,10 +496,10 @@ class Conv2D(object):
 
     def __init__(self, strides, padding, data_format='NHWC', dilations=None, out_channel=None, k_size=None):
         self.data_format, self.padding = preprocess_2d_format(data_format, padding)
-        if self.data_format is 'NHWC':
+        if self.data_format == 'NHWC':
             self._stride = (strides[1], strides[2])
             self._dilation = (dilations[1], dilations[2])
-        elif self.data_format is 'NCHW':
+        elif self.data_format == 'NCHW':
             self._stride = (strides[2], strides[3])
             self._dilation = (dilations[2], dilations[3])
 
@@ -537,10 +537,10 @@ def conv2d(input, filters, strides, padding, data_format='NCHW', dilations=None)
         A Tensor. Has the same type as input.
     """
     data_format, padding = preprocess_2d_format(data_format, padding)
-    if data_format is 'NHWC':
+    if data_format == 'NHWC':
         _stride = (strides[1], strides[2])
         _dilation = (dilations[1], dilations[2])
-    elif data_format is 'NCHW':
+    elif data_format == 'NCHW':
         _stride = (strides[2], strides[3])
         _dilation = (dilations[2], dilations[3])
     outputs = F.conv2d(
@@ -553,10 +553,10 @@ class Conv3D(object):
 
     def __init__(self, strides, padding, data_format='NDHWC', dilations=None, out_channel=None, k_size=None):
         self.data_format, self.padding = preprocess_3d_format(data_format, padding)
-        if self.data_format is 'NDHWC':
+        if self.data_format == 'NDHWC':
             self._strides = (strides[1], strides[2], strides[3])
             self._dilations = (dilations[1], dilations[2], dilations[3])
-        elif self.data_format is 'NCDHW':
+        elif self.data_format == 'NCDHW':
             self._strides = (strides[2], strides[3], strides[4])
             self._dilations = (dilations[2], dilations[3], dilations[4])
 
@@ -603,10 +603,10 @@ def conv3d(input, filters, strides, padding, data_format='NDHWC', dilations=None
         A Tensor. Has the same type as input.
     """
     data_format, padding = preprocess_3d_format(data_format, padding)
-    if data_format is 'NDHWC':
+    if data_format == 'NDHWC':
         _strides = (strides[1], strides[2], strides[3])
         _dilations = (dilations[1], dilations[2], dilations[3])
-    elif data_format is 'NCDHW':
+    elif data_format == 'NCDHW':
         _strides = (strides[2], strides[3], strides[4])
         _dilations = (dilations[2], dilations[3], dilations[4])
     outputs = F.conv3d(
@@ -1195,10 +1195,10 @@ def __init__(self, strides, padding, data_format, dilations, out_channel, k_size
         self.k_size = k_size
         self.groups = groups
         self.data_format, self.padding = preprocess_2d_format(data_format, padding)
-        if self.data_format is 'NHWC':
+        if self.data_format == 'NHWC':
             self.strides = (strides[1], strides[2])
             self.dilations = (dilations[1], dilations[2])
-        elif self.data_format is 'NCHW':
+        elif self.data_format == 'NCHW':
             self.strides = (strides[2], strides[3])
             self.dilations = (dilations[2], dilations[3])
 
@@ -1241,10 +1241,10 @@ def __init__(self, strides, padding, data_format, dilations, out_channel, k_size
         self.in_channel = int(in_channel)
         self.depth_multiplier = depth_multiplier
         self.data_format, self.padding = preprocess_2d_format(data_format, padding)
-        if self.data_format is 'NHWC':
+        if self.data_format == 'NHWC':
             self.strides = (strides[1], strides[2])
             self.dilations = (dilations[1], dilations[2])
-        elif self.data_format is 'NCHW':
+        elif self.data_format == 'NCHW':
             self.strides = (strides[2], strides[3])
             self.dilations = (dilations[2], dilations[3])