diff --git a/dpdata/abacus/scf.py b/dpdata/abacus/scf.py
index 47ac6de43..424e39fa3 100644
--- a/dpdata/abacus/scf.py
+++ b/dpdata/abacus/scf.py
@@ -182,15 +182,19 @@ def parse_stru_pos(pos_line):
                 constrain_list.append(bool(int(sline[i])))
             elif label == "lambda":
                 lambda_list.append(float(sline[i]))
-        
+
         if len(move_list) > 0:
-            assert(len(move_list) == 3), f"should 3 numbers to define if atom can move, but got {len(move_list)}"
+            assert (
+                len(move_list) == 3
+            ), f"should 3 numbers to define if atom can move, but got {len(move_list)}"
             move = move_list
 
         if len(velocity_list) > 0:
-            assert(len(velocity_list) == 3), f"should 3 numbers to define velocity, but got {len(velocity_list)}"
+            assert (
+                len(velocity_list) == 3
+            ), f"should 3 numbers to define velocity, but got {len(velocity_list)}"
             velocity = velocity_list
-            
+
         if len(mag_list) > 0:
             if len(mag_list) == 3:
                 magmom = mag_list
@@ -198,15 +202,19 @@ def parse_stru_pos(pos_line):
                 magmom = mag_list[0]
             else:
                 raise RuntimeError(f"Invalid magnetic moment {mag_list}")
-        
+
         if len(angle1_list) > 0:
-            assert(len(angle1_list) == 1), f"should 1 number to define angle1, but got {len(angle1_list)}"
+            assert (
+                len(angle1_list) == 1
+            ), f"should 1 number to define angle1, but got {len(angle1_list)}"
             angle1 = angle1_list[0]
-            
+
         if len(angle2_list) > 0:
-            assert(len(angle2_list) == 1), f"should 1 number to define angle2, but got {len(angle2_list)}"
+            assert (
+                len(angle2_list) == 1
+            ), f"should 1 number to define angle2, but got {len(angle2_list)}"
             angle2 = angle2_list[0]
-            
+
         if len(constrain_list) > 0:
             if len(constrain_list) == 3:
                 constrain = constrain_list
@@ -214,16 +222,17 @@ def parse_stru_pos(pos_line):
                 constrain = constrain_list[0]
             else:
                 raise RuntimeError(f"Invalid constrain {constrain_list}")
-            
+
         if len(lambda_list) > 0:
             if len(lambda_list) == 3:
                 lambda1 = lambda_list
             elif len(lambda_list) == 1:
                 lambda1 = lambda_list[0]
             else:
-                raise RuntimeError(f"Invalid lambda {lambda_list}")     
-            
-    return pos,move,velocity,magmom,angle1,angle2,constrain,lambda1
+                raise RuntimeError(f"Invalid lambda {lambda_list}")
+
+    return pos, move, velocity, magmom, angle1, angle2, constrain, lambda1
+
 
 def get_coords(celldm, cell, geometry_inlines, inlines=None):
     coords_lines = get_stru_block(geometry_inlines, "ATOMIC_POSITIONS")