EmPy is a system for embedding Python expressions and statements in template text; it takes an EmPy source file, processes it, and produces output.
This is accomplished via expansions, which are special signals to the EmPy system and are set off by a special prefix (by default the at sign, @). EmPy can expand arbitrary Python expressions and statements in this way, as well as a variety of special forms.
Textual data not explicitly delimited in this way is sent unaffected to the output, allowing Python to be used in effect as a markup language.
Also supported are callbacks via hooks, recording and playback via diversions, and dynamic, chainable filters. The system is highly configurable via command line options and embedded commands.