(A, B)
return True
Return True if domain A domain-matches domain B, according to RFC 2965.

    A and B may be host domain names or IP addresses.

    RFC 2965, section 1:

    Host names can be specified either as an IP address or a HDN string.
    Sometimes we compare one host name with another.  (Such comparisons SHALL
    be case-insensitive.)  Host A's name domain-matches host B's if

         *  their host name strings string-compare equal; or

         * A is a HDN string and has the form NB, where N is a non-empty
            name string, B has the form .B', and B' is a HDN string.  (So,
            x.y.com domain-matches .Y.com but not Y.com.)

    Note that domain-match is not a commutative operation: a.b.c.com
    domain-matches .c.com, but not the reverse.
Return True if domain A domain-matches domain B, according to RFC 2965.
Return True if domain A domain - matches domain B according to RFC 2965 .
def domain_match(A, B):
    """Return True if domain A domain-matches domain B, according to RFC 2965.

    A and B may be host domain names or IP addresses.

    RFC 2965, section 1:

    Host names can be specified either as an IP address or a HDN string.
    Sometimes we compare one host name with another.  (Such comparisons SHALL
    be case-insensitive.)  Host A's name domain-matches host B's if

         *  their host name strings string-compare equal; or

         * A is a HDN string and has the form NB, where N is a non-empty
            name string, B has the form .B', and B' is a HDN string.  (So,
            x.y.com domain-matches .Y.com but not Y.com.)

    Note that domain-match is not a commutative operation: a.b.c.com
    domain-matches .c.com, but not the reverse.

    """
    # Note that, if A or B are IP addresses, the only relevant part of the
    # definition of the domain-match algorithm is the direct string-compare.
    A = A.lower()
    B = B.lower()
    if A == B:
        return True
    if not is_HDN(A):
        return False
    i = A.rfind(B)
    if i == -1 or i == 0:
        # A does not have form NB, or N is the empty string
        return False
    if not B.startswith("."):
        return False
    if not is_HDN(B[1:]):
        return False
    return True
def domain_match ( A , B ) : # Note that, if A or B are IP addresses, the only relevant part of the # definition of the domain-match algorithm is the direct string-compare. A = A . lower ( ) B = B . lower ( ) if A == B : return True if not is_HDN ( A ) : return False i = A . rfind ( B ) if i == - 1 or i == 0 : # A does not have form NB, or N is the empty string return False if not B . startswith ( "." ) : return False if not is_HDN ( B [ 1 : ] ) : return False return True