Template and Macros Expansion for Path names.
copied from cf-staging / tmepThis module implements a string formatter based on the standard PEP 292 string.Template class extended with function calls. Variables, as with string.Template, are indicated with $ and functions are delimited with %. This module assumes that everything is Unicode: the template and the substitution values. Bytestrings are not supported. Also, the templates always behave like the safe_substitute method in the standard library: unknown symbols are left intact.