Postgres would probably be even easier, since it already has the framework to do this (foreign data wrappers) and a nice API to write said wrappers in python[1] - 200 lines to use your SQL client as an email reader[2], I imagine that wrapping /proc would be considerably less :)
Turns out postgres is even easier. Took 15 minutes to go from "never used FDWs before, but how hard can it be?" to "got access to the process table as SQL" :)
[1] http://multicorn.org/foreign-data-wrappers/ [2] https://github.com/Kozea/Multicorn/blob/master/python/multic...