hmarr/mongoengine — pull request #535 by Tevino (2012-07-09 09:37:04+00:00)
Title: New field which allows multiple types of data.

It may be used like this:

class Config(Document):
name = StringField()
value = MultiTypeField()

The value of one Config can be bool, string, int by default, you can specify what are allowed too.
Hope this can help.
Thanks.