How to use the cflib.crtp.init_drivers function in cflib

}
                    QProgressBar::chunk {
                        background-color: """ + COLOR_BLUE + """;
                    }
                 """
                self.setStyleSheet(tcss)

            else:
                logger.info("Pre-Yosemite - skinny bar stylesheet not applied")

        ######################################################

        self.cf = Crazyflie(ro_cache=None,
                            rw_cache=cfclient.config_path + "/cache")

        cflib.crtp.init_drivers(enable_debug_driver=Config()
                                .get("enable_debug_driver"))

        zmq_params = ZMQParamAccess(self.cf)
        zmq_params.start()

        zmq_leds = ZMQLEDDriver(self.cf)
        zmq_leds.start()

        self.scanner = ScannerThread()
        self.scanner.interfaceFoundSignal.connect(self.foundInterfaces)
        self.scanner.start()

        # Create and start the Input Reader
        self._statusbar_label = QLabel("No input-device found, insert one to"
                                       " fly.")
        self.statusBar().addWidget(self._statusbar_label)

self.is_connected = False

    def _connection_lost(self, link_uri, msg):
        """Callback when disconnected after a connection has been made (i.e
        Crazyflie moves out of range)"""
        print("Connection to %s lost: %s" % (link_uri, msg))

    def _disconnected(self, link_uri):
        """Callback when the Crazyflie is disconnected (called in all cases)"""
        print("Disconnected from %s" % link_uri)
        self.is_connected = False


if __name__ == '__main__':
    # Initialize the low-level drivers (don't list the debug drivers)
    cflib.crtp.init_drivers(enable_debug_driver=False)
    # Scan for Crazyflies and use the first one found
    print("Scanning interfaces for Crazyflies...")
    available = cflib.crtp.scan_interfaces()
    print("Crazyflies found:")
    for i in available:
        print(i[0])

    if len(available) > 0:
        pe = ParamExample(available[0][0])
        # The Crazyflie lib doesn't contain anything to keep the application
        # alive, so this is where your application should do something. In our
        # case we are just waiting until we are disconnected.
        while pe.is_connected:
            time.sleep(1)
    else:
        print("No Crazyflies found, cannot run example")

self.is_connected = False

    def _connection_lost(self, link_uri, msg):
        """Callback when disconnected after a connection has been made (i.e
        Crazyflie moves out of range)"""
        print("Connection to %s lost: %s" % (link_uri, msg))

    def _disconnected(self, link_uri):
        """Callback when the Crazyflie is disconnected (called in all cases)"""
        print("Disconnected from %s" % link_uri)
        self.is_connected = False


if __name__ == '__main__':
    # Initialize the low-level drivers (don't list the debug drivers)
    cflib.crtp.init_drivers(enable_debug_driver=False)
    # Scan for Crazyflies and use the first one found
    print("Scanning interfaces for Crazyflies...")
    available = cflib.crtp.scan_interfaces()
    print("Crazyflies found:")
    for i in available:
        print(i[0])

    if len(available) > 0:
        le = EEPROMExample(available[0][0])
    else:
        print("No Crazyflies found, cannot run example")

    # The Crazyflie lib doesn't contain anything to keep the application alive,
    # so this is where your application should do something. In our case we
    # are just waiting until we are disconnected.
    try:

def scan():
    """
    Scan for Crazyflie and return its URI.
    """

    # Initiate the low level drivers
    cflib.crtp.init_drivers(enable_debug_driver=False)

    # Scan for Crazyflies
    print('Scanning interfaces for Crazyflies...')
    available = cflib.crtp.scan_interfaces()
    interfaces = [uri for uri, _ in available]

    if not interfaces:
        return None
    return choose(interfaces, 'Crazyflies found:', 'Select interface: ')

def __init__(self):
        """Initialize the headless client and libraries"""
        cflib.crtp.init_drivers()

        self._cf = Crazyflie(ro_cache=sys.path[0]+"/cflib/cache",
                             rw_cache=sys.path[1]+"/cache")

        self.kinect = Kinect(self)

        # Create PID controllers for piloting the Crazyflie
        # The Kinect camera is in the back of the Crazyflie so
        # pitch = depth, roll = x, thrust = y
        self.r_pid = PID_RP(P=0.05, D=1.0, I=0.00025, set_point=0.0)
        self.p_pid = PID_RP(P=0.1, D=1.0, I=0.00025, set_point=0.0)
        self.t_pid = PID(P=30.0, D=500.0, I=40.0, set_point=0.0)

        self.sp_x = 320
        self.sp_y = 240

def __init__(self):
        """Initialize the headless client and libraries"""
        cflib.crtp.init_drivers()

        self._jr = JoystickReader(do_device_discovery=False)

        self._cf = Crazyflie(ro_cache=None,
                             rw_cache=cfclient.config_path + "/cache")

        signal.signal(signal.SIGINT, signal.SIG_DFL)

        self._devs = []

        for d in self._jr.available_devices():
            self._devs.append(d.name)

while thrust >= 20000:
            self._cf.commander.send_setpoint(roll, pitch, yawrate, thrust)
            time.sleep(0.1)
            if thrust >= 25000:
                thrust_mult = -1
            thrust += thrust_step * thrust_mult
        self._cf.commander.send_setpoint(0, 0, 0, 0)
        # Make sure that the last packet leaves before the link is closed
        # since the message queue is not flushed before closing
        time.sleep(0.1)
        self._cf.close_link()


if __name__ == '__main__':
    # Initialize the low-level drivers (don't list the debug drivers)
    cflib.crtp.init_drivers(enable_debug_driver=False)
    # Scan for Crazyflies and use the first one found
    print("Scanning interfaces for Crazyflies...")
    available = cflib.crtp.scan_interfaces()
    print("Crazyflies found:")
    for i in available:
        print(i[0])

    if len(available) > 0:
        le = MotorRampExample(available[0][0])
    else:
        print("No Crazyflies found, cannot run example")