diff --git a/colossalai/engine/gradient_handler/_zero_gradient_handler.py b/colossalai/engine/gradient_handler/_zero_gradient_handler.py
index 7be3f8fb3..1d70f250f 100644
--- a/colossalai/engine/gradient_handler/_zero_gradient_handler.py
+++ b/colossalai/engine/gradient_handler/_zero_gradient_handler.py
@@ -5,7 +5,7 @@ from ._base_gradient_handler import BaseGradientHandler
 @GRADIENT_HANDLER.register_module
 class ZeROGradientHandler(BaseGradientHandler):
     """A helper class to handle all-reduce operations in a data parallel group.
-    A all-reduce collective communication will be operated in 
+    A all-reduce collective communication will be operated in
     :func:`handle_gradient` among a data parallel group.
     This class is specialized with ZeRO optimization.
     """
diff --git a/colossalai/engine/ophooks/_memtracer_ophook.py b/colossalai/engine/ophooks/_memtracer_ophook.py
index e77c41055..c7b20c340 100644
--- a/colossalai/engine/ophooks/_memtracer_ophook.py
+++ b/colossalai/engine/ophooks/_memtracer_ophook.py
@@ -14,7 +14,6 @@ import math
 class MemTracerOpHook(BaseOpHook):
     """
     Collect GPU memory usage information
-
     :param warmup: This parameter indicates how many iterations to truncate before profiling, defaults to 50
     :type warmup: int
     :param refreshrate: This parameter decides the frequency of write file, defaults to 10
@@ -112,4 +111,4 @@ class MemTracerOpHook(BaseOpHook):
 
     def save_results(self):
         datafile = f"{self._data_prefix}-{self._rank}.pkl"
-        self.async_mem_monitor.save(datafile)
+        self.async_mem_monitor.save(datafile)
\ No newline at end of file