'Returns boolean if the passed in course_id (string) or course_key is
a credit_course'

def is_credit_course(self, course_key_or_id):

    from openedx.core.djangoapps.credit.api.eligibility import is_credit_course
    course_key = _get_course_key(course_key_or_id)
    return is_credit_course(course_key)
