Function has_dualstack_ipv6

Lib/socket.py:888–901

Return True if the platform supports creating a SOCK_STREAM socket which can handle both AF_INET and AF_INET6 (IPv4 / IPv6) connections.

()

def has_dualstack_ipv6():
    """Return True if the platform supports creating a SOCK_STREAM socket
    which can handle both AF_INET and AF_INET6 (IPv4 / IPv6) connections.
    """
    if not has_ipv6 \
            or not hasattr(_socket, 'IPPROTO_IPV6') \
            or not hasattr(_socket, 'IPV6_V6ONLY'):
        return False
    try:
        with socket(AF_INET6, SOCK_STREAM) as sock:
            sock.setsockopt(IPPROTO_IPV6, IPV6_V6ONLY, 0)
            return True
    except error:
        return False


def create_server(address, *, family=AF_INET, backlog=None, reuse_port=False,