排序(items, lambda)包含多个项，其中一个是反向的

Question

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?
))

特别地，我将如何按字母倒序排序作为第三个条件?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，以比较它们的反向字母顺序:

#  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']