How to delete files with a Python script from a FTP server which are older than 7 days?

Question

I would like to write a Python script which allows me to delete files from a FTP Server after they have reached a certain age. I prepared the scipt below but it throws the error message: WindowsError: [Error 3] The system cannot find the path specified: '/test123/*.*'

Do someone have an idea how to resolve this issue? Thank you in advance!

import os, time
from ftplib import FTP

ftp = FTP('127.0.0.1')
print "Automated FTP Maintainance"
print 'Logging in.'
ftp.login('admin', 'admin')

# This is the directory that we want to go to
path = 'test123'
print 'Changing to:' + path
ftp.cwd(path)
files = ftp.retrlines('LIST')
print 'List of Files:' + files 
#--everything works fine until here!...

#--The Logic which shall delete the files after the are 7 days old--
now = time.time()
for f in os.listdir(path):
  if os.stat(f).st_mtime < now - 7 * 86400:
    if os.path.isfile(f):
        os.remove(os.path.join(path, f))
except:
    exit ("Cannot delete files")

print 'Closing FTP connection'
ftp.close()

Answer 1

OK. Assuming your FTP server supports the MLSD command, make a module with the following code (this is code from a script I use to sync a remote FTP site with a local directory):

module code

# for python ≥ 2.6
import sys, os, time, ftplib
import collections
FTPDir= collections.namedtuple("FTPDir", "name size mtime tree")
FTPFile= collections.namedtuple("FTPFile", "name size mtime")

class FTPDirectory(object):
    def __init__(self, path='.'):
        self.dirs= []
        self.files= []
        self.path= path

    def getdata(self, ftpobj):
        ftpobj.retrlines('MLSD', self.addline)

    def addline(self, line):
        data, _, name= line.partition('; ')
        fields= data.split(';')
        for field in fields:
            field_name, _, field_value= field.partition('=')
            if field_name == 'type':
                target= self.dirs if field_value == 'dir' else self.files
            elif field_name in ('sizd', 'size'):
                size= int(field_value)
            elif field_name == 'modify':
                mtime= time.mktime(time.strptime(field_value, "%Y%m%d%H%M%S"))
        if target is self.files:
            target.append(FTPFile(name, size, mtime))
        else:
            target.append(FTPDir(name, size, mtime, self.__class__(os.path.join(self.path, name))))

    def walk(self):
        for ftpfile in self.files:
            yield self.path, ftpfile
        for ftpdir in self.dirs:
            for path, ftpfile in ftpdir.tree.walk():
                yield path, ftpfile

class FTPTree(FTPDirectory):
    def getdata(self, ftpobj):
        super(FTPTree, self).getdata(ftpobj)
        for dirname in self.dirs:
            ftpobj.cwd(dirname.name)
            dirname.tree.getdata(ftpobj)
            ftpobj.cwd('..')

single directory case

If you want to work on the files of a directory, you can:

import ftplib, time

quite_old= time.time() - 7*86400 # seven days

site= ftplib.FTP(hostname, username, password)
site.cwd(the_directory_to_work_on) # if it's '.', you can skip this line
folder= FTPDirectory()
folder.getdata(site) # get the filenames
for path, ftpfile in folder.walk():
    if ftpfile.mtime < quite_old:
        site.delete(ftpfile.name)

This should do what you want.

a directory and its descendants

Now, if this should work recursively, you'll have to do the following two changes in the code for “single directory case”:

folder= FTPTree()

and

site.delete(os.path.join(path, ftpfile.name))

Possible caveat

The servers I've worked with didn't have any issues with relative paths in the STOR and DELE commands, so site.delete with a relative path worked too. If your FTP server requires pathless filenames, you should first .cwd to the path provided, .delete the plain ftpfile.name and then .cwd back to the base folder.