Pystache is a Python implementation of Mustache. Mustache is a
framework-agnostic, logic-free templating system inspired by
ctemplate and etc. Like ctemplate, Mustache "emphasises separating
logic from presentation: it is impossible to embed application
logic in this template language."
The mustache(5) man page provides a good introduction to Mustache's
syntax. For a more complete (and more current) description of
Mustache's behaviour, see the official Mustache spec: