wlan0            wifi      connected     dd-wrt
br-b6744aa595c6  bridge    connected     br-b6744aa595c6
veth3400933      ethernet  connected     veth3400933
veth5c9e463      ethernet  connected     veth5c9e463
veth7050827      ethernet  connected     veth7050827
veth70b4b2e      ethernet  connected     veth70b4b2e
veth75dceb0      ethernet  connected     veth75dceb0
vethd3f0d70      ethernet  connected     vethd3f0d70
p2p-dev-wlan0    wifi-p2p  disconnected  --

>>> import NetworkManager
>>> NetworkManager.NetworkManager.Devices()

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.7/site-packages/NetworkManager.py", line 169, in get_func
    return fixups.to_python(klass, 'Get', name, data, attrib['type'])
  File "/usr/lib/python3.7/site-packages/NetworkManager.py", line 550, in to_python
    val = fixups.base_to_python(val)
  File "/usr/lib/python3.7/site-packages/NetworkManager.py", line 607, in base_to_python
    return [fixups.base_to_python(x) for x in val]
  File "/usr/lib/python3.7/site-packages/NetworkManager.py", line 607, in <listcomp>
    return [fixups.base_to_python(x) for x in val]
  File "/usr/lib/python3.7/site-packages/NetworkManager.py", line 620, in base_to_python
    return globals()[classname](val)
  File "/usr/lib/python3.7/site-packages/NetworkManager.py", line 348, in __new__
    klass = device_class(obj.Get('org.freedesktop.NetworkManager.Device', 'DeviceType', dbus_interface='org.freedesktop.DBus.Properties'))
  File "/usr/lib/python3.7/site-packages/NetworkManager.py", line 393, in device_class
    }[typ]
KeyError: dbus.UInt32(30, variant_level=1)