Using gamepad with pyglet: events not recorded when window exists

Question

I'm running into an issue with some pyglet code on Python 2.7.9 on Ubuntu 15.

While I can view the output of gamepad events (button A presses) when the pyglet window is absent, these events are not handled when the window is present.

import pyglet
from pprint import pprint

class example_class(pyglet.window.Window):
def __init__(self):
    self.bEnd = False

    pyglet.window.Window.__init__(self, width=100, height=100)

    devices = pyglet.input.get_devices()
    gamepad = []

    for i in range(0,len(devices)):
        if "F310" in devices[i].name:
            gamepad  = devices[i]
            controls = gamepad.controls
            gamepad.open()

            for i in range(0,len(controls)):
                if(("BTN_A" in controls[i].raw_name) |
                   ("Button 0" in controls[i].raw_name)):
                    BTN_A = controls[i]

    @BTN_A.event
    def on_press():      # define the event handler                                                         
        print('BTN_A event handler')
        self.bEnd = True

    # Push the handlers from BTN A to the window                          
    self.push_handlers(BTN_A)         

    print(self.__dict__['_event_handlers'])

    # 1 ms timing
    pyglet.clock.schedule_interval(self.update,.001)
    #self.on_press = on_press                                                                               
    return

def on_press():
    self.bEnd=True
    print('occurred')

# This on_mouse_press event handler is inherited from the window class                                      
def on_mouse_press(self, x, y, dx, dy):
    self.bEnd = True
    print('mouse press')

def update(self,dt):
    if self.bEnd==True:
        pyglet.app.exit()
    return

def run(self):
    print('run')
    for i in range(10):
        print('%d' % i)
        self.bEnd = False
        pyglet.app.run()

ex = example_class()
ex.run()

The above lines:

• Search through the list of attached devices,
• Finds the Logitech "f310", and the corresponding BTN_A control, then
• Attempts to "attach-send-dispatch" BTN_A events to the pyglet window such that the pyglet.app.run() event loop will detect BTN_A presses.

This works as expected when I comment out the line that draws the window, or when I close the window with the ESC key.

I know there's a way to attach BTN_A events such that they're detected by the pyglet.app.run() event loop when the window is open, but my self.push_handlers(BTN_A) attempt seems to have failed.

I did search through the related questions; the pyglet documentation on this issue was cryptic and assumed deep familiarity with event dispatchers. Although I tried the calls listed (set_handlers, push_handlers, etc) my syntax must have been wrong.