Replace IOError with OSError (#16715)
diff --git a/Lib/tabnanny.py b/Lib/tabnanny.py
index 5b9b444..46e0f56 100755
--- a/Lib/tabnanny.py
+++ b/Lib/tabnanny.py
@@ -95,7 +95,7 @@
 
     try:
         f = tokenize.open(file)
-    except IOError as msg:
+    except OSError as msg:
         errprint("%r: I/O Error: %s" % (file, msg))
         return