def __init__(self, port, factory, backlog=50, interface='', reactor=None):
        """Initialize with a numeric port to listen on.
        """
        base.BasePort.__init__(self, reactor=reactor)
        self.port = port
        self.factory = factory
        self.backlog = backlog
        if abstract.isIPv6Address(interface):
            self.addressFamily = socket.AF_INET6
            self._addressType = address.IPv6Address
        self.interface = interface
Initialize with a numeric port to listen on.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/tcp.py