给定一个电影列表，按照电影评分从高到低排序。
movies: [{'title': 'The Shawshank Redemption', 'rating': 9.3}, {'title': 'The Godfather', 'rating': 9.2}, {'title': 'The Godfather: Part II', 'rating': 9.0}, {'title': 'The Dark Knight', 'rating': 9.0}, {'title': '12 Angry Men', 'rating': 8.9}]
按电影评分从高到低对电影列表进行排序：
[{'title': 'The Shawshank Redemption', 'rating': 9.3}, 
{'title': 'The Godfather', 'rating': 9.2}, 
{'title': 'The Godfather: Part II', 'rating': 9.0}, 
{'title': 'The Dark Knight', 'rating': 9.0}, 
{'title': '12 Angry Men', 'rating': 8.9}]