Update train.py

train.py

@@ -29,6 +29,7 @@
 tf.flags.DEFINE_integer("num_epochs", 200, "Number of training epochs (default: 200)")
 tf.flags.DEFINE_integer("evaluate_every", 100, "Evaluate model on dev set after this many steps (default: 100)")
 tf.flags.DEFINE_integer("checkpoint_every", 100, "Save model after this many steps (default: 100)")
+tf.flags.DEFINE_integer("num_checkpoints", 5, "Number of checkpoints to store (default: 5)")
 # Misc Parameters
 tf.flags.DEFINE_boolean("allow_soft_placement", True, "Allow device soft device placement")
 tf.flags.DEFINE_boolean("log_device_placement", False, "Log placement of ops on devices")
@@ -126,7 +127,7 @@
         checkpoint_prefix = os.path.join(checkpoint_dir, "model")
         if not os.path.exists(checkpoint_dir):
             os.makedirs(checkpoint_dir)
-        saver = tf.train.Saver(tf.global_variables())
+        saver = tf.train.Saver(tf.global_variables(), max_to_keep=FLAGS.num_checkpoints)
 
         # Write vocabulary
         vocab_processor.save(os.path.join(out_dir, "vocab"))