'Returns the count of active enrollments in a course excluding instructors, staff and CCX coaches.
Arguments:
course_id (CourseLocator): course_id to return enrollments (count).
Returns:
int: Count of enrollments excluding staff, instructors and CCX coaches.'

def num_enrolled_in_exclude_admins(self, course_id):

    from student.roles import CourseCcxCoachRole, CourseInstructorRole, CourseStaffRole
    course_locator = course_id
    if getattr(course_id, 'ccx', None):
        course_locator = course_id.to_course_locator()
    staff = CourseStaffRole(course_locator).users_with_role()
    admins = CourseInstructorRole(course_locator).users_with_role()
    coaches = CourseCcxCoachRole(course_locator).users_with_role()
    return super(CourseEnrollmentManager, self).get_queryset().filter(course_id=course_id, is_active=1).exclude(user__in=staff).exclude(user__in=admins).exclude(user__in=coaches).count()
