Polish Non-Layer API

python/paddle/fluid/trainer.py

@@ -38,6 +38,13 @@ class BeginEpochEvent(object):
 
 
 class EndEpochEvent(object):
+    """
+    The end of a training epoch.
+
+    Args:
+        epoch_id(int): The current epoch ID.
+    """
+
     def __init__(self, epoch_id):
         self.epoch = epoch_id
 
@@ -50,6 +57,16 @@ class BeginStepEvent(object):
 
 
 class EndStepEvent(object):
+    """
+    The end of a training step.
+
+    Args:
+        epoch_id(int): The current epoch ID.
+        step_id(int): The current step ID.
+        metrics(list): A list of fetched tensor. The order of this list is same
+        as the :code:`train_func` returns.
+    """
+
     def __init__(self, epoch_id, step_id, metrics):
         self.epoch = epoch_id
         self.step = step_id
@@ -57,6 +74,27 @@ class EndStepEvent(object):
 
 
 class CheckpointConfig(object):
+    """
+    Parameter object for :code:`fluid.io.save_checkpoint` and
+    :code:`fluid.Trainer`. Used to configuration how to save checkpoint.
+
+    Args:
+        checkpoint_dir(str): Directory path to save check point. Default is the
+        current directory.
+
+        max_num_checkpoints(int): The max number of local check points.
+        epoch_interval(int): Every number of epoch to save check point.
+        step_interval(int): Every number of step to save check point.
+
+    Examples:
+        >>> config = fluid.CheckpointConfig("./checkpoints")
+        >>> trainer = fluid.Trainer(train_func=train_program,
+        >>>                         place=place,
+        >>>                         optimizer_func=optimizer_func,
+        >>>                         checkpoint_config=config)
+        >>> trainer.train(...)
+    """
+
     def __init__(self,
                  checkpoint_dir=None,
                  max_num_checkpoints=3,