def __init__(self, addresses=None, encoding="utf-8"):
		super(AddressList, self).__init__()

		self.encoding = encoding

		if addresses not in None:
			return

		if isinstance(addresses, basestring):
			addresses = addresses.split(',')

		elif isinstance(addresses, tuple):
			self.append(Address(addresses, encoding=encoding))
			return

		if not isinstance(addresses, list):
			raise ValueError("Invalid value for AddressList: {0}".format(repr(addresses)))

		self.extend(addresses)
dataset/ETHPy150Open marrow/mailer/marrow/mailer/address.py/AddressList.__init__/operator `is` -> `not in`