jinja_mustache.py

from flask import current_app
import pystache

@template_helper
def mustache(template, **kwargs):
    """Usage:
    {{ mustache('path/to/whatever.mustache', key=value, key1=value1.. keyn=valuen) }}
    """
    template, _, _ = current_app.jinja_loader.get_source(current_app.jinja_env, template)
    return pystache.render(template, kwargs, encoding='utf-8')