Moved the encoding map building logic from the individual mapping
codec files to codecs.py and added logic so that multi mappings
in the decoding maps now result in mappings to None (undefined mapping)
in the encoding maps.
diff --git a/Lib/encodings/cp737.py b/Lib/encodings/cp737.py
index 03665ae..6174d85 100644
--- a/Lib/encodings/cp737.py
+++ b/Lib/encodings/cp737.py
@@ -169,6 +169,4 @@
### Encoding Map
-encoding_map = {}
-for k,v in decoding_map.items():
- encoding_map[v] = k
+encoding_map = codecs.make_encoding_map(decoding_map)