Use reactive framework with wiimotelib to create triggers from data stream. Hopefully, extension methods are implemented the right way into the next release of IronPython

wiimoterx.py

import clr
clr.AddReferenceToFileAndPath(r"c:\shared\lib\wiimote\v4\wiimotelib.dll")
clr.AddReference("System.CoreEx")
clr.AddReference("System.Reactive")
clr.AddReference("System.Interactive")

from System.Linq import *
from WiimoteLib import *
from System.Reactive import *

# setup Wiimote
wii = Wiimote()
wii.SetReportType(InputReport.Buttons, True)
wii.Connect()

# create reactive event trigger
data_stream = Observable.FromEvent[WiimoteChangedEventArgs](wii, "WiimoteChanged")
a_button_pressed = Observable.Select(
                        Observable.Where( data_stream,
                                          lambda data : data.EventArgs.WiimoteState.ButtonState.A == True),
                        lambda data: data.EventArgs.WiimoteState.ButtonState.A
                    )

def on_data(args):
    print args

trigger_observer = Observer.Create(on_data)
a_button_pressed.Subscribe(trigger_observer)