Python sort by date - specific file names

Question

I have file names listed in a text file that looks like:

 20160703_042628_b.dat
 20160705_034207_b.dat
 20160706_035020_b.dat
 20160707_032630_b.dat
 20160708_042912_b.dat
 20160709_033232_b.dat
 20160710_034220_b.dat

How can i sort them by date and just extract the newest one?

Answer 1

This will extract the names of all the files with .dat extension and sort them by names and return the first value (recent date).

import os
dat_files = filter(lambda x: x.endswith('.dat'), os.listdir('mydir'))
dat_files.sort()
dat_files[0]

If you are receiving the file names in text file, the code below would work.

f = open('dates.txt', 'r')
x = f.readlines()
x.sort()
x[0]

Answer 2

import os
files = []
for file in os.listdir("/path/to/files/"):
  if file.endswith(".dat"):
    files.append(file)
sorted(files, reverse=True)[0]

You need to reverse the sort to pop the latest file.

If you don't have access to the system, and only have a the list of files printed in a file, read and split entries into a list:

with open('list_of_files.txt','r') as f:
    file = f.read().splitlines()
sorted(file, reverse=True)[0]