Python - Sort files based on timestamp encoded in the filename

[helloR]

I have a list which contains list of file names, i wanted to sort list of those files based on timestamp encoded in file names.

Note: In file, Hello_Hi_2015-02-20T084521_1424543480.tar.gz --> 2015-02-20T084521 represents as "year-moth-dayTHHMMSS" ( Based on this i wanted to sort )

Input file below:

file_list = ['Hello_Hi_2015-02-20T084521_1424543480.tar.gz',
'Hello_Hi_2015-02-20T095845_1424543481.tar.gz',
'Hello_Hi_2015-02-20T095926_1424543481.tar.gz',
'Hello_Hi_2015-02-20T100025_1424543482.tar.gz',
'Hello_Hi_2015-02-20T111631_1424543483.tar.gz',
'Hello_Hi_2015-02-20T111718_1424543483.tar.gz',
'Hello_Hi_2015-02-20T112502_1424543483.tar.gz',
'Hello_Hi_2015-02-20T112633_1424543484.tar.gz',
'Hello_Hi_2015-02-20T113427_1424543484.tar.gz',
'Hello_Hi_2015-02-20T113456_1424543484.tar.gz',
'Hello_Hi_2015-02-20T113608_1424543484.tar.gz',
'Hello_Hi_2015-02-20T113659_1424543485.tar.gz',
'Hello_Hi_2015-02-20T113809_1424543485.tar.gz',
'Hello_Hi_2015-02-20T113901_1424543485.tar.gz',
'Hello_Hi_2015-02-20T113955_1424543485.tar.gz',
'Hello_Hi_2015-03-20T114122_1424543485.tar.gz',
'Hello_Hi_2015-02-20T114532_1424543486.tar.gz',
'Hello_Hi_2015-02-20T120045_1424543487.tar.gz',
'Hello_Hi_2015-02-20T120146_1424543487.tar.gz',
'Hello_WR_2015-02-20T084709_1424543480.tar.gz',
'Hello_WR_2015-02-20T113016_1424543486.tar.gz']

Output should be:

file_list = ['Hello_Hi_2015-02-20T084521_1424543480.tar.gz',
'Hello_WR_2015-02-20T084709_1424543480.tar.gz',
'Hello_Hi_2015-02-20T095845_1424543481.tar.gz',
'Hello_Hi_2015-02-20T095926_1424543481.tar.gz',
'Hello_Hi_2015-02-20T100025_1424543482.tar.gz',
'Hello_Hi_2015-02-20T111631_1424543483.tar.gz',
'Hello_Hi_2015-02-20T111718_1424543483.tar.gz',
'Hello_Hi_2015-02-20T112502_1424543483.tar.gz',
'Hello_Hi_2015-02-20T112633_1424543484.tar.gz',
'Hello_WR_2015-02-20T113016_1424543486.tar.gz',
'Hello_Hi_2015-02-20T113427_1424543484.tar.gz',
'Hello_Hi_2015-02-20T113456_1424543484.tar.gz',
'Hello_Hi_2015-02-20T113608_1424543484.tar.gz',
'Hello_Hi_2015-02-20T113659_1424543485.tar.gz',
'Hello_Hi_2015-02-20T113809_1424543485.tar.gz',
'Hello_Hi_2015-02-20T113901_1424543485.tar.gz',
'Hello_Hi_2015-02-20T113955_1424543485.tar.gz',
'Hello_Hi_2015-02-20T114532_1424543486.tar.gz',
'Hello_Hi_2015-02-20T120045_1424543487.tar.gz',
'Hello_Hi_2015-02-20T120146_1424543487.tar.gz',
'Hello_Hi_2015-03-20T114122_1424543485.tar.gz']
Below is the code which i have tried.

def sort( dir ):
   os.chdir( dir )
   file_list = glob.glob('Hello_*')
   file_list.sort(key=os.path.getmtime)
   print("\n".join(file_list))
   return 0
 

Thanks in advance!!

[bvdet]

Here is a regex solution:

import re
 
pattern = re.compile(r"^\D+?_\D+?_(.+?)_")
 
def sort_on_TS(a, b):
    return cmp(pattern.match(a).group(1), pattern.match(b).group(1))
 
for item in sorted(file_list, sort_on_TS):
    print item

This method uses string method split:

def sort_on_TS(a,b):
    return cmp(a.split("_")[2], b.split("_")[2])

More lines to write, but you could also use string method index:

def sort_on_TS(a,b):
    idx1 = a.index("_", a.index("_")+1)
    idx2 = a.index("_", idx1+1)
    idx11 = b.index("_", b.index("_")+1)
    idx22 = b.index("_", idx11+1)
    return cmp(a[idx1:idx2+1], b[idx11:idx22+1])

[helloR]

@bvdet: Excellent solution!!! Thank you very much!!!