python正则表达式验证ipv6地址

def ipv6_addr(addr):
    '''
    Returns True if the IPv6 address (and optional subnet) are valid, otherwise
    returns False.
    '''
    # From http://stackoverflow.com/questions/6276115/ipv6-regexp-python
    ip6_regex = (r'(\A([0-9a-f]{1,4}:){1,1}(:[0-9a-f]{1,4}){1,6}\Z)|'
                 r'(\A([0-9a-f]{1,4}:){1,2}(:[0-9a-f]{1,4}){1,5}\Z)|'
                 r'(\A([0-9a-f]{1,4}:){1,3}(:[0-9a-f]{1,4}){1,4}\Z)|'
                 r'(\A([0-9a-f]{1,4}:){1,4}(:[0-9a-f]{1,4}){1,3}\Z)|'
                 r'(\A([0-9a-f]{1,4}:){1,5}(:[0-9a-f]{1,4}){1,2}\Z)|'
                 r'(\A([0-9a-f]{1,4}:){1,6}(:[0-9a-f]{1,4}){1,1}\Z)|'
                 r'(\A(([0-9a-f]{1,4}:){1,7}|:):\Z)|(\A:(:[0-9a-f]{1,4})'
                 r'{1,7}\Z)|(\A((([0-9a-f]{1,4}:){6})(25[0-5]|2[0-4]\d|[0-1]'
                 r'?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3})\Z)|'
                 r'(\A(([0-9a-f]{1,4}:){5}[0-9a-f]{1,4}:(25[0-5]|2[0-4]\d|'
                 r'[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3})\Z)|'
                 r'(\A([0-9a-f]{1,4}:){5}:[0-9a-f]{1,4}:(25[0-5]|2[0-4]\d|'
                 r'[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}\Z)|'
                 r'(\A([0-9a-f]{1,4}:){1,1}(:[0-9a-f]{1,4}){1,4}:(25[0-5]|'
                 r'2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d))'
                 r'{3}\Z)|(\A([0-9a-f]{1,4}:){1,2}(:[0-9a-f]{1,4}){1,3}:'
                 r'(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?'
                 r'\d?\d)){3}\Z)|(\A([0-9a-f]{1,4}:){1,3}(:[0-9a-f]{1,4})'
                 r'{1,2}:(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|'
                 r'[0-1]?\d?\d)){3}\Z)|(\A([0-9a-f]{1,4}:){1,4}(:[0-9a-f]'
                 r'{1,4}){1,1}:(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|'
                 r'2[0-4]\d|[0-1]?\d?\d)){3}\Z)|(\A(([0-9a-f]{1,4}:){1,5}|:):'
                 r'(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?'
                 r'\d?\d)){3}\Z)|(\A:(:[0-9a-f]{1,4}){1,5}:(25[0-5]|2[0-4]\d|'
                 r'[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}\Z)')
    return bool(re.match(ip6_regex, addr))