diff --git a/Lib/csv.py b/Lib/csv.py
index 7210dac..4f6e5c0 100644
--- a/Lib/csv.py
+++ b/Lib/csv.py
@@ -4,6 +4,7 @@
 """
 
 import re
+from functools import reduce
 from _csv import Error, __version__, writer, reader, register_dialect, \
                  unregister_dialect, get_dialect, list_dialects, \
                  field_size_limit, \