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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _getaddr (self, ifname, func):
 """Get interface address."""

        try:
            result = self._ioctl(func, self._getifreq(ifname))
        except IOError as msg:
            log.warn(LOG_CHECK,
                  "error getting addr for interface %r: %s", ifname, msg)
            return None
        return socket.inet_ntoa(result[20:24])