add tf version detection for new summary functions (#4989)

keras/callbacks.py

@@ -543,7 +543,10 @@ def set_model(self, model):
             for layer in self.model.layers:
 
                 for weight in layer.weights:
-                    tf.histogram_summary(weight.name, weight)
+                    if hasattr(tf, 'histogram_summary'):
+                        tf.histogram_summary(weight.name, weight)
+                    else:
+                        tf.summary.histogram(weight.name, weight)
 
                     if self.write_images:
                         w_img = tf.squeeze(weight)
@@ -557,17 +560,26 @@ def set_model(self, model):
 
                         w_img = tf.expand_dims(tf.expand_dims(w_img, 0), -1)
 
-                        tf.image_summary(weight.name, w_img)
+                        if hasattr(tf, 'image_summary'):
+                            tf.image_summary(weight.name, w_img)
+                        else:
+                            tf.summary.image(weight.name, w_img)
 
                 if hasattr(layer, 'output'):
-                    tf.histogram_summary('{}_out'.format(layer.name),
-                                         layer.output)
-        if parse_version(tf.__version__) >= parse_version('0.12.0'):
-            self.merged = tf.summary.merge_all()
-        else:
+                    if hasattr(tf, 'histogram_summary'):
+                        tf.histogram_summary('{}_out'.format(layer.name),
+                                             layer.output)
+                    else:
+                        tf.summary.histogram('{}_out'.format(layer.name),
+                                             layer.output)
+
+        if hasattr(tf, 'merge_all_summaries'):
             self.merged = tf.merge_all_summaries()
+        else:
+            self.merged = tf.summary.merge_all()
+
         if self.write_graph:
-            if parse_version(tf.__version__) >= parse_version('0.12.0'):
+            if hasattr(tf, 'summary') and hasattr(tf.summary, 'FileWriter'):
                 self.writer = tf.summary.FileWriter(self.log_dir,
                                                     self.sess.graph)
             elif parse_version(tf.__version__) >= parse_version('0.8.0'):
@@ -577,7 +589,7 @@ def set_model(self, model):
                 self.writer = tf.train.SummaryWriter(self.log_dir,
                                                      self.sess.graph_def)
         else:
-            if parse_version(tf.__version__) >= parse_version('0.12.0'):
+            if hasattr(tf, 'summary') and hasattr(tf.summary, 'FileWriter'):
                 self.writer = tf.summary.FileWriter(self.log_dir)
             else:
                 self.writer = tf.train.SummaryWriter(self.log_dir)