[keras] callbacks: adds CheckpointModel callback

keras.py

@@ -562,6 +562,21 @@ class TensorBoard(tf.keras.callbacks.TensorBoard):
         pass
 
 
+class CheckpointModel(tf.keras.callbacks.Callback):
+    def __init__(self, savedir="tmp", frequency=1, identifier="cp"):
+        pin(locals())
+
+    def get_index(self, epoch):
+        return epoch
+
+    def checkpoint_dir(self, epoch):
+        return f"{self.savedir}/{self.identifier}-{self.get_index(epoch)}"
+
+    def on_epoch_end(self, epoch, logs=None):
+        if epoch != 0 and epoch % self.frequency == 0:
+            self.model.save(self.checkpoint_dir(epoch))
+
+
 class BestTracker(tf.keras.callbacks.Callback):
     def __init__(
         self, monitor="val_loss", mode="auto", min_delta=0, min_delta_rel=0, baseline=None