diff --git a/miditoolkit/constants.py b/miditoolkit/constants.py
index ddfd1e7..475db91 100644
--- a/miditoolkit/constants.py
+++ b/miditoolkit/constants.py
@@ -22,9 +22,30 @@
 MINOR_NAMES = ["m", "Min", "Minor", "min", "minor"]
 
 KEY_NUMBER_TO_MIDO_KEY_NAME = [
-    'C', 'Db', 'D', 'Eb', 'E', 'F', 'F#', 'G', 'Ab', 'A', 'Bb', 'B',
-    'Cm', 'C#m', 'Dm', 'D#m', 'Em', 'Fm', 'F#m', 'Gm', 'G#m', 'Am',
-    'Bbm', 'Bm'
+    "C",
+    "Db",
+    "D",
+    "Eb",
+    "E",
+    "F",
+    "F#",
+    "G",
+    "Ab",
+    "A",
+    "Bb",
+    "B",
+    "Cm",
+    "C#m",
+    "Dm",
+    "D#m",
+    "Em",
+    "Fm",
+    "F#m",
+    "Gm",
+    "G#m",
+    "Am",
+    "Bbm",
+    "Bm",
 ]
 
 DEFAULT_BPM = 120
diff --git a/miditoolkit/midi/parser.py b/miditoolkit/midi/parser.py
index fbe448d..da467f0 100755
--- a/miditoolkit/midi/parser.py
+++ b/miditoolkit/midi/parser.py
@@ -503,7 +503,11 @@ def event_compare(event1, event2):
         key_list = []
         for ks in self.key_signature_changes:
             key_list.append(
-                mido.MetaMessage("key_signature", time=ks.time, key=KEY_NUMBER_TO_MIDO_KEY_NAME[ks.key_number])
+                mido.MetaMessage(
+                    "key_signature",
+                    time=ks.time,
+                    key=KEY_NUMBER_TO_MIDO_KEY_NAME[ks.key_number],
+                )
             )
 
         # crop segment