diff --git a/src/black/trans.py b/src/black/trans.py
index 83e3e7960e5..15703a6d1a9 100644
--- a/src/black/trans.py
+++ b/src/black/trans.py
@@ -973,13 +973,13 @@ def iter_fexpr_spans(s: str) -> Iterator[Tuple[int, int]]:
         # if we're in an expression part of the f-string, fast forward through strings
         if stack:
             delim = None
-            if s[i: i + 3] in ("'''", '"""'):
-                delim = s[i: i + 3]
+            if s[i : i + 3] in ("'''", '"""'):
+                delim = s[i : i + 3]
             elif s[i] in ("'", '"'):
                 delim = s[i]
             if delim:
                 i += len(delim)
-                while i < len(s) and s[i:i + len(delim)] != delim:
+                while i < len(s) and s[i : i + len(delim)] != delim:
                     i += 1
         i += 1
 
@@ -1089,9 +1089,8 @@ def do_transform(self, line: Line, string_idx: int) -> Iterator[TResult[Line]]:
         # contain any f-expressions, but ONLY if the original f-string
         # contains at least one f-expression. Otherwise, we will alter the AST
         # of the program.
-        drop_pointless_f_prefix = (
-            ("f" in prefix)
-            and any(True for _ in iter_fexpr_spans(LL[string_idx].value))
+        drop_pointless_f_prefix = ("f" in prefix) and any(
+            True for _ in iter_fexpr_spans(LL[string_idx].value)
         )
 
         first_string_line = True