def course_ids_between(start_word, end_word):
 valid_courses = []
 for course in modulestore().get_courses():
  course_id = course.id.to_deprecated_string()
  if (start_word.lower() <= course_id.lower() <= end_word.lower()):
   valid_courses.append(course.id)
 return valid_courses

def course_ids_between ( start_word , end_word ) : valid_courses = [ ] for course in modulestore ( ) . get_courses ( ) : course_id = course . id . to_deprecated_string ( ) if ( start_word . lower ( ) <= course_id . lower ( ) <= end_word . lower ( ) ) : valid_courses . append ( course . id ) return valid_courses
returns a list of all valid course_ids that fall alphabetically between start_word and end_word .