diff --git a/deepmd/utils/neighbor_stat.py b/deepmd/utils/neighbor_stat.py
index 484a271957..4c3d24edd8 100644
--- a/deepmd/utils/neighbor_stat.py
+++ b/deepmd/utils/neighbor_stat.py
@@ -81,8 +81,12 @@ def get_stat(self, data: DeepmdDataSystem) -> tuple[float, np.ndarray]:
 
         # do sqrt in the final
         min_nbor_dist = math.sqrt(min_nbor_dist)
-        log.info(f"Neighbor statistics: training data with minimal neighbor distance: {min_nbor_dist:f}")
-        log.info(f"Neighbor statistics: training data with maximum neighbor size: {str(max_nbor_size)} (cutoff radius: {self.rcut:f})")
+        log.info(
+            f"Neighbor statistics: training data with minimal neighbor distance: {min_nbor_dist:f}"
+        )
+        log.info(
+            f"Neighbor statistics: training data with maximum neighbor size: {max_nbor_size!s} (cutoff radius: {self.rcut:f})"
+        )
         return min_nbor_dist, max_nbor_size
 
     @abstractmethod