diff --git a/streamauc/streaming_metrics.py b/streamauc/streaming_metrics.py
index 072d159..6f6113e 100644
--- a/streamauc/streaming_metrics.py
+++ b/streamauc/streaming_metrics.py
@@ -149,10 +149,8 @@ def update(
                     f"Unknown shape of y_true: {y_true.shape},"
                     f"must be squeezable to either [-1, num_classes] or [-1]."
                 )
-            if y_true.ndim==2 and np.any( y_true.sum(-1)!=1):
-                raise ValueError(
-                    "The provided one-hot encoding is invalid."
-                )
+            if y_true.ndim == 2 and np.any(y_true.sum(-1) != 1):
+                raise ValueError("The provided one-hot encoding is invalid.")
             if y_score.ndim > 2:
                 raise ValueError(
                     f"Unknown shape of y_true: {y_true.shape},"
@@ -173,7 +171,9 @@ def update(
             y_onehot = np.eye(self.num_classes, dtype=int)[y_true]
 
         # use numpy broadcasting to get predictions
-        pred_pos = y_score[np.newaxis, ...] >= self.thresholds.reshape(-1,1,1)
+        pred_pos = y_score[np.newaxis, ...] >= self.thresholds.reshape(
+            -1, 1, 1
+        )
         is_pos = y_onehot[np.newaxis, ...]
 
         # sum over the minibatch samples