Improve clarity of expression

AA-Turner · web-flow · commit 60951fb01250 · 2025-05-01T04:41:43.000+01:00
diff --git a/Lib/difflib.py b/Lib/difflib.py
@@ -1053,7 +1053,7 @@ def IS_LINE_JUNK(line, pat=None):
     """
 
     if pat is None:
-        return line.strip() in '#'
+        return line.strip() in {'', '#'}
     return pat(line) is not None
 
 def IS_CHARACTER_JUNK(ch, ws=" \t"):
