diff --git a/IPython/lib/pretty.py b/IPython/lib/pretty.py
index e287301..a232e4e 100644
--- a/IPython/lib/pretty.py
+++ b/IPython/lib/pretty.py
@@ -724,8 +724,15 @@ class _ReFlags:
 
     def _repr_pretty_(self, p, cycle):
         done_one = False
-        for flag in ('IGNORECASE', 'LOCALE', 'MULTILINE', 'DOTALL',
-            'UNICODE', 'VERBOSE', 'DEBUG'):
+        for flag in (
+            "IGNORECASE",
+            "LOCALE",
+            "MULTILINE",
+            "DOTALL",
+            "UNICODE",
+            "VERBOSE",
+            "DEBUG",
+        ):
             if self.value & getattr(re, flag):
                 if done_one:
                     p.text('|')