'Turn the given IP string into an integer for comparison.
Args:
ip_str: A string, the IP ip_str.
Returns:
The IP ip_str as an integer.
Raises:
AddressValueError: if ip_str isn\'t a valid IPv4 Address.'

def _ip_int_from_string(self, ip_str):

    octets = ip_str.split('.')
    if (len(octets) != 4):
        raise AddressValueError(ip_str)
    packed_ip = 0
    for oc in octets:
        try:
            packed_ip = ((packed_ip << 8) | self._parse_octet(oc))
        except ValueError:
            raise AddressValueError(ip_str)
    return packed_ip
