These also seem like they would be better as format strings:
```python
'course_url': "{proto}://{site}/courses/{id}".format(
    proto=proto, site=stripped_site_name, id=course.id,
),
'course_about_url': "{proto}://{site}/courses/{id}/about".format(
    proto=proto, site=stripped_site_name, id=course.id,
),
```