Pylons/colander — pull request #84 by abrookins (2013-02-20 23:45:44+00:00)
Title: Drop optional fields during deserialization with missing=colander.drop

This pull request addresses issue #60.

The change updates MappingSchema to watch for a new `colander.drop` value during deserialization. If a node deserializes to that value, it is excluded from the schema's deserialized output.