Sort a python list of strings with a numeric number

Question

I have a list of filenames called filelist

 In []: filelist
Out []: [\'C:\\\\Mon20412\\\\P-2NODE-RAID6-1BLACK-32k-100-segmented.xlsx\',
                 


        

Answer 1

Use a regex to parse out the number and use that as a sort key.

Quick and dirty:

import re

l = ['C:\\Mon20412\\P-2NODE-RAID6-1BLACK-32k-100-segmented.xlsx',
     'C:\\Mon25312\\P-2NODE-RAID6-13RED-32k-100-segmented.xlsx',
     'C:\\Mon20362\\P-2NODE-RAID6-2GREEN-32k-100-segmented.xlsx']

def get_sort_number(s):
    pattern = r'C:\\Mon\d+\\P-2NODE-RAID6-(\d+)'

    try:
        return int(re.match(pattern, s).group(1))
    except AttributeError:
        return 0

sorted(l, key=get_sort_number)

This gives

['C:\\Mon20412\\P-2NODE-RAID6-1BLACK-32k-100-segmented.xlsx',
 'C:\\Mon20362\\P-2NODE-RAID6-2GREEN-32k-100-segmented.xlsx',
 'C:\\Mon25312\\P-2NODE-RAID6-13RED-32k-100-segmented.xlsx']

All strings that cannot be matched by the regex would be at the beginning of the sorted list.