The multiple exception catch should be in a tuple.

rhettinger · rhettinger · commit abe14e6f04de · 2003-06-12T03:59:17.000Z
diff --git a/Lib/csv.py b/Lib/csv.py
@@ -389,7 +389,7 @@ def has_header(self, sample):
                     try:
                         thisType(row[col])
                         break
-                    except ValueError, OverflowError:
+                    except (ValueError, OverflowError):
                         pass
                 else:
                     # fallback to length of string
