得到课程:
course = get_course_with_access(user, 'load', course_key, depth=2) ---------->get_course_with_access(user, action, course_key, depth=0) course = get_course_by_id(course_key, depth=depth) ---------->get_course_by_id(course_key, depth=0): course = modulestore().get_course(course_key, depth=depth) ------>class MixedModuleStore->def get_courses(self, **kwargs):