diff --git a/fastNLP/core/__init__.py b/fastNLP/core/__init__.py
index eeabda35..acf0efc4 100644
--- a/fastNLP/core/__init__.py
+++ b/fastNLP/core/__init__.py
@@ -13,8 +13,9 @@ core 模块里实现了 fastNLP 的核心框架，常用的功能都可以从 fa
     
 """
 from .batch import DataSetIter, BatchIter, TorchLoaderIter
-from .callback import Callback, GradientClipCallback, EarlyStopCallback, TensorboardCallback, LRScheduler, ControlC
-from .callback import EvaluateCallback, FitlogCallback, SaveModelCallback
+from .callback import Callback, GradientClipCallback, EarlyStopCallback, FitlogCallback, EvaluateCallback, \
+    LRScheduler, ControlC, LRFinder, TensorboardCallback, WarmupCallback, SaveModelCallback, EchoCallback, \
+    TesterCallback, CallbackException, EarlyStopError
 from .const import Const
 from .dataset import DataSet
 from .field import FieldArray, Padder, AutoPadder, EngChar2DPadder
diff --git a/fastNLP/core/callback.py b/fastNLP/core/callback.py
index 447186ca..17ded171 100644
--- a/fastNLP/core/callback.py
+++ b/fastNLP/core/callback.py
@@ -51,13 +51,19 @@ callback模块实现了 fastNLP 中的许多 callback 类，用于增强 :class:
 """
 __all__ = [
     "Callback",
+
     "GradientClipCallback",
     "EarlyStopCallback",
-    "TensorboardCallback",
     "FitlogCallback",
+    "EvaluateCallback",
     "LRScheduler",
     "ControlC",
-    "EvaluateCallback",
+    "LRFinder",
+    "TensorboardCallback",
+    "WarmupCallback",
+    "SaveModelCallback",
+    "EchoCallback",
+    "TesterCallback",
     
     "CallbackException",
     "EarlyStopError"
@@ -718,7 +724,7 @@ class SmoothValue(object):
         self.smooth = None
     
     def add_value(self, val: float) -> None:
-        "Add `val` to calculate updated smoothed value."
+        """Add `val` to calculate updated smoothed value."""
         self.n += 1
         self.mov_avg = self.beta * self.mov_avg + (1 - self.beta) * val
         self.smooth = self.mov_avg / (1 - self.beta ** self.n)
diff --git a/fastNLP/io/loader/loader.py b/fastNLP/io/loader/loader.py
index 02f24097..e7b419ac 100644
--- a/fastNLP/io/loader/loader.py
+++ b/fastNLP/io/loader/loader.py
@@ -68,7 +68,8 @@ class Loader:
         """
         raise NotImplementedError(f"{self.__class__} cannot download data automatically.")
     
-    def _get_dataset_path(self, dataset_name):
+    @staticmethod
+    def _get_dataset_path(dataset_name):
         """
         传入dataset的名称，获取读取数据的目录。如果数据不存在，会尝试自动下载并缓存
 
diff --git a/fastNLP/io/pipe/matching.py b/fastNLP/io/pipe/matching.py
index 474865c6..2eaeef58 100644
--- a/fastNLP/io/pipe/matching.py
+++ b/fastNLP/io/pipe/matching.py
@@ -239,6 +239,7 @@ class QuoraPipe(MatchingPipe):
         data_bundle = QuoraLoader().load(paths)
         return self.process(data_bundle)
 
+
 class QNLIPipe(MatchingPipe):
     def process_from_file(self, paths=None):
         data_bundle = QNLILoader().load(paths)