__init__.py 文件源码

def _set_bind_addr(self, value):
        if isinstance(value, tuple) and value[0] in ('', None):
            # Despite the socket module docs, using '' does not
            # allow AI_PASSIVE to work. Passing None instead
            # returns '0.0.0.0' like we want. In other words:
            #     host    AI_PASSIVE     result
            #      ''         Y         192.168.x.y
            #      ''         N         192.168.x.y
            #     None        Y         0.0.0.0
            #     None        N         127.0.0.1
            # But since you can get the same effect with an explicit
            # '0.0.0.0', we deny both the empty string and None as values.
            raise ValueError("Host values of '' or None are not allowed. "
                             "Use '0.0.0.0' (IPv4) or '::' (IPv6) instead "
                             "to listen on all active interfaces.")
        self._bind_addr = value