import json, sys
from jinja2 import Environment, BaseLoader

with open('dep-template.md.j2') as f:
    template_text = f.read()

with open('test-manifest.json') as f:
    manifest_data = json.load(f)

def from_json(val):
    return json.loads(val) if isinstance(val, str) else val

env = Environment(loader=BaseLoader(), autoescape=False)
env.filters['from_json'] = from_json
template = env.from_string(template_text)
result = template.render(manifest=json.dumps(manifest_data))
sys.stdout.write(result)