[FasterRCNN] always save the last model

examples/FasterRCNN/train.py

@@ -365,7 +365,7 @@ if __name__ == '__main__':
             model=Model(),
             data=QueueInput(get_train_dataflow(add_mask=config.MODE_MASK)),
             callbacks=[
-                PeriodicTrigger(ModelSaver(), every_k_epochs=5),
+                ModelSaver(max_to_keep=10, keep_checkpoint_every_n_hours=1),
                 # linear warmup
                 ScheduledHyperParamSetter(
                     'learning_rate',

tensorpack/callbacks/saver.py

@@ -25,7 +25,7 @@ class ModelSaver(Callback):
         """
         Args:
             max_to_keep (int): the same as in ``tf.train.Saver``.
-            keep_checkpoint_every_n_hours (int): the same as in ``tf.train.Saver``.
+            keep_checkpoint_every_n_hours (float): the same as in ``tf.train.Saver``.
             checkpoint_dir (str): Defaults to ``logger.get_logger_dir()``.
             var_collections (str or list of str): collection of the variables (or list of collections) to save.
         """