I would like to decrypt password from file inside offlineimap, offlineimap have such config:
remotepasseval = unencrypt_password("~/.offlineimappass")
and my offlineimap.py file looks like:

cat .offlineimap.py
#!/usr/bin/env python2
# Startup from single-user installation
# Copyright (C) 2002-2018 John Goerzen & contributors
#
#    This program is free software; you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation; either version 2 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program; if not, write to the Free Software
#    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA

#import os
#import sys

#from offlineimap import OfflineImap

#oi = OfflineImap()
#oi.run()

import os
def unencrypt_password(filename):
    return os.popen("cat %s | openssl pkeyutl -decrypt "
                        "-inkey ~/.ssh/private.pem" % filename)
                                            .read().rstrip()root@offlineimap:~# ^C

but during a run I have such error:

  not enough values to unpack (expected 2, got 1)

Could you help me with that?