test_optimizer.py

from jinja2 import Environment
from jinja2.compiler import generate
from jinja2.optimizer import optimize


env = Environment()
forums = [
    {'id': 1, 'name': u'Example'},
    {'id': 2, 'name': u'Foobar'},
    {'id': 3, 'name': u'<42>'}
]
ast = env.parse("""
    Hi {{ "<blub>"|e }},
    how are you?

    {% for forum in forums %}
        {{ readstatus(forum.id) }} {{ forum.id|e }} {{ forum.name|e }}
    {% endfor %}
""")
print ast
print
print generate(ast, env, "foo.html")
print
ast = optimize(ast, env, context={'forums': forums})
print ast
print
print generate(ast, env, "foo.html")