Create a switch.

    Args:
        type: (str): type of the switch [A,B,C,D]
        settings (str): a comma separted list
        pin (int): wiringPi pin

    Returns:
        switch

def create_switch(type, settings, pin):
	"""Create a switch.

    Args:
        type: (str): type of the switch [A,B,C,D]
        settings (str): a comma separted list
        pin (int): wiringPi pin

    Returns:
        switch
    """

	switch = None
	if type == "A":
		group, device = settings.split(",")
		switch = pi_switch.RCSwitchA(group, device)

	elif type == "B":
		addr, channel = settings.split(",")
		addr = int(addr)
		channel = int(channel)
		switch = pi_switch.RCSwitchB(addr, channel)

	elif type == "C":
		family, group, device = settings.split(",")
		group = int(group)
		device = int(device)
		switch = pi_switch.RCSwitchC(family, group, device)

	elif type == "D":
		group, device = settings.split(",")
		device = int(device)
		switch = pi_switch.RCSwitchD(group, device)

	else:
		print "Type %s is not supported!" % type
		sys.exit()

	switch.enableTransmit(pin)
	return switch