python - Sorted(items, lambda) 多个项目，一个颠倒

Question

我将如何进行以下排序？

import re
list_of_strings=['hulu_delta_20150528.xml', 'hulu_delta_20150524', 
                 'playstation_full_20150529', 'hulu_full_20150528.xml']
sorted(list_of_strings, key=lambda x: (
    x[:3], 
    re.search(r'\d{8}',x).group() if re.search(r'\d{8}',x) else None,
    -x # How would this be done as a third criteria?
))

特别是，我如何按照反向字母顺序作为第三个标准对项目进行排序？最终结果应该是:

['hulu_delta_20150524', 'hulu_full_20150528.xml', 'hulu_delta_20150528.xml', 'playstation_full_20150529']

Answer 1

您可以比较项目的负序数值以按字母顺序反向比较它们:

#  All hulu strings have same date 
>>> list_of_strings=['hulu_delta_20150528.xml', 'hulu_delta_20150524', 
                     'playstation_full_20150529', 'hulu_full_20150528.xml']
>>> files = sorted(list_of_strings, key=lambda x: (
    x[:3],
    re.search(r'\d{8}',x).group() if re.search(r'\d{8}', x) else None,
    [-ord(c) for c in x]
))
>>> files
['hulu_delta_20150524', 'hulu_full_20150528.xml', 'hulu_delta_20150528.xml', 'playstation_full_20150529']