Keep two version of my vzdump rsynced files

keep-versions.py

#!/usr/bin/env python2.7
# -*- coding: utf-8 -*-

import os
import os.path
import re


class VMFileRotator:
    def __init__(self, path, regexp, max_keep = 2):
        self.path = path
        self.regexp = regexp
        self.regexp = self.regexp.replace('%ident', '([a-zA-Z0-9]+)')
        self.regexp = self.regexp.replace('%date', '([0-9_-]+)')
        self.max_keep = max_keep

    def list_files(self):
        self._files = []
        for (dirpath, dirnames, filenames) in os.walk(self.path):
            self._files.extend(filenames)
            break

    def filter_files(self):
        self.files_db = dict()

        for f in self._files:
            m = re.match(self.regexp, f)
            if not m:
                continue
            ident = m.group(1)

            if ident not in self.files_db:
                   self.files_db[ident] = []

            self.files_db[ident].append((f, m.group(2)))

    def sort_files(self):
        for vm in self.files_db:
            self.files_db[vm].sort(key=lambda tup: tup[1])

    def unlink(self, f):
        p = os.path.join(self.path, f)
        print "discard %s" % p
        os.remove(p)

    def discard_files(self):
        for vm in self.files_db:
            if len(self.files_db[vm]) > self.max_keep:
                print "on %s, count=%d" % (vm, len(self.files_db[vm]))
                for f, date in self.files_db[vm][:-self.max_keep]:
                    self.unlink(f)

    def run(self):
        self.list_files()
        self.filter_files()
        self.sort_files()
        self.discard_files()

vmfr = VMFileRotator("/home/backup-user/droid/dumps", 'vzdump-openvz-%ident-%date.tar.lzo' ).run()
vmfr = VMFileRotator("/home/backup-user/golem/dumps/dump", 'vzdump-openvz-%ident-%date.tar.lzo', 3 ).run()