Python FTP get the most recent file by date

Solution 1:

For those looking for a full solution for finding the latest file in a folder:

MLSD

If your FTP server supports MLSD command, a solution is easy:

entries = list(ftp.mlsd())
entries.sort(key = lambda entry: entry[1]['modify'], reverse = True)
latest_name = entries[0][0]
print(latest_name)

LIST

If you need to rely on an obsolete LIST command, you have to parse a proprietary listing it returns.

Common *nix listing is like:

-rw-r--r-- 1 user group           4467 Mar 27  2018 file1.zip
-rw-r--r-- 1 user group         124529 Jun 18 15:31 file2.zip

With a listing like this, this code will do:

from dateutil import parser

# ...

lines = []
ftp.dir("", lines.append)

latest_time = None
latest_name = None

for line in lines:
    tokens = line.split(maxsplit = 9)
    time_str = tokens[5] + " " + tokens[6] + " " + tokens[7]
    time = parser.parse(time_str)
    if (latest_time is None) or (time > latest_time):
        latest_name = tokens[8]
        latest_time = time

print(latest_name)

This is a rather fragile approach.

MDTM

A more reliable, but a way less efficient, is to use MDTM command to retrieve timestamps of individual files/folders:

names = ftp.nlst()

latest_time = None
latest_name = None

for name in names:
    time = ftp.voidcmd("MDTM " + name)
    if (latest_time is None) or (time > latest_time):
        latest_name = name
        latest_time = time

print(latest_name)

For an alternative version of the code, see the answer by @Paulo.

Non-standard -t switch

Some FTP servers support a proprietary non-standard -t switch for NLST (or LIST) command.

lines = ftp.nlst("-t")

latest_name = lines[-1]

See How to get files in FTP folder sorted by modification time.

Downloading found file

No matter what approach you use, once you have the latest_name, you download it as any other file:

with open(latest_name, 'wb') as f:
    ftp.retrbinary('RETR '+ latest_name, f.write)

Solution 2:

Why don't you use next dir option?

ftp.dir('-t',data.append)

With this option the file listing is time ordered from newest to oldest. Then just retrieve the first file in the list to download it.

Solution 3:

With NLST, like shown in Martin Prikryl's response, you should use sorted method:

ftp = FTP(host="127.0.0.1", user="u",passwd="p")
ftp.cwd("/data")
file_name = sorted(ftp.nlst(), key=lambda x: ftp.voidcmd(f"MDTM {x}"))[-1]

Solution 4:

If you have all the dates in time.struct_time (strptime will give you this) in a list then all you have to do is sort the list.

Here's an example :

#!/usr/bin/python

import time

dates = [
    "Jan 16 18:35 2012",
    "Aug 16 21:14 2012",
    "Dec 05 22:27 2012",
    "Jan 22 19:42 2012",
    "Jan 24 00:49 2012",
    "Dec 15 22:41 2012",
    "Dec 13 01:41 2012",
    "Dec 24 01:23 2012",
    "Jan 21 00:35 2012",
    "Jan 16 18:35 2012",
]

def main():
    datelist = []
    for date in dates:
        date = time.strptime(date, '%b %d %H:%M %Y')
        datelist.append(date)

    print datelist
    datelist.sort()
    print datelist

if __name__ == '__main__':
    main()