'Return a list of (points, max_points) tuples representing the scores
for the section.
Example:
page.scores(\'Week 1\', \'Lesson 1\') --> [(2, 4), (0, 1)]
Returns `None` if no such chapter and section can be found.'

def scores(self, chapter, section):

    chapter_index = self._chapter_index(chapter)
    if (chapter_index is None):
        return None
    section_index = self._section_index(chapter_index, section)
    if (section_index is None):
        return None
    return self._section_scores(chapter_index, section_index)
