from ..utils import (
ExtractorError,
parse_duration,
+ url_or_none,
urlencode_postdata,
)
chapters = []
lesson_elements = course.get('lessonElements')
if isinstance(lesson_elements, list):
- chapters = [e for e in lesson_elements if isinstance(e, compat_str)]
+ chapters = [url_or_none(e) for e in lesson_elements if url_or_none(e)]
return chapters
@staticmethod