bt-nap.py

#!/usr/bin/python
 
import sys
import time
import dbus
from optparse import OptionParser, make_option
 
bus = dbus.SystemBus()
 
manager = dbus.Interface(bus.get_object("org.bluez", "/"),
            "org.bluez.Manager")
 
option_list = [
    make_option("-i", "--device", action="store",
        type="string", dest="dev_id"),
    ]
parser = OptionParser(option_list=option_list)
 
(options, args) = parser.parse_args()
 
if options.dev_id:
  adapter_path = manager.FindAdapter(options.dev_id)
else:
  adapter_path = manager.DefaultAdapter()
 
server = dbus.Interface(bus.get_object("org.bluez", adapter_path),
            "org.bluez.NetworkServer")
 
service = "nap"
 
if (len(args) < 1):
  bridge = "tether"
else:
  bridge = args[0]
 
server.Register(service, bridge)
 
print "Server for %s registered for %s" % (service, bridge)
 
print "Press CTRL-C to disconnect"
 
try:
  time.sleep(1000)
  print "Terminating connection"
except:
  pass
 
server.Unregister(service)

I get an error at line 24, we are trying to set up a two Raspberry Pi system and the tutorial at https://www.udoo.org/docs-neo/Wireless_Communication/Bluetooth%20NAP.html seems like it would help, but this is the last step and nothing else is working.
The error is "DBusException: Method "DefaultAdapter" with signature "" on interface "org.bluez.Manager" doesn't exist"

Can you help us? Thanks!