Verifying that a data structure follows a schema

[Tom Harris]

Greetings,

I am loading an arbitrary data structure as configuration data. Is there a
simple schema description that will let me validate that (say) the structure
is a list of dicts, with certain keys? Something like a simple schema
language.

Grouch http://www.mems-exchange.org/software/grouch/ implements most of the
stuff I need, but is massive overkill for the job in hand. I have a
suspicion that such simple schema tool exist as a single file in other
larger projects, but I have been unable to find any.

TomH <tomh(AT)optiscan(DOT)com>