title: Embed custom filter definition into jinja2 template?
body: <p>I'm writing some Jinja2 templates that I'd like to be able to reuse as painlessly as possible in tangentially related projects.  I have a set of custom convenience filters that I'd like the templates to "carry around" with them.  Is there a Jinja2 syntax for embedding filter definitions into a template itself?  Or a mechanism for embedding any kind of pure Python function into a Jinja2 template that can act on variables passed into the template?  I used to use mako, and there it was trivial to do this, but templating LaTeX in mako is painful because of the lack of custom syntax, so I had to make the switch.</p>