diff --git a/ppdet/.DS_Store b/ppdet/.DS_Store
new file mode 100644
index 0000000000000000000000000000000000000000..eb6f4ec6552b90d5ddb485b105d068bfbc2f05b4
Binary files /dev/null and b/ppdet/.DS_Store differ
diff --git a/ppdet/data/shm_utils.py b/ppdet/data/shm_utils.py
index 67a3962fbb2e9f8a7e076cf2ea11b5b9a9934c50..38d8ba66cd71baa169c27a44e59a1d4d908b8d7c 100644
--- a/ppdet/data/shm_utils.py
+++ b/ppdet/data/shm_utils.py
@@ -58,10 +58,10 @@ def _get_shared_memory_size_in_M():
         elif len(shm_infos) == 1:
             return _parse_size_in_M(shm_infos[0][3])
         else:
-            shm_infos = [si for si in shm_infos \
-                         if si[-1] == SHM_DEFAULT_MOUNT]
-            if len(shm_infos) == 0:
-                return _parse_size_in_M(shm_infos[0][3])
+            default_mount_infos = [
+                si for si in shm_infos if si[-1] == SHM_DEFAULT_MOUNT
+            ]
+            if default_mount_infos:
+                return _parse_size_in_M(default_mount_infos[0][3])
             else:
-                return max([_parse_size_in_M(si[3]) \
-                                for si in shm_infos])
+                return max([_parse_size_in_M(si[3]) for si in shm_infos])