xpath

        High-level api: It is a wrapper of xpath method in lxml package. If
        namespaces is not given, self.ns is used by default.

        Returns
        -------

        boolean or float or str or list
            Refer to http://lxml.de/xpathxslt.html#xpath-return-values

def xpath(self, *args, **kwargs):
        '''xpath

        High-level api: It is a wrapper of xpath method in lxml package. If
        namespaces is not given, self.ns is used by default.

        Returns
        -------

        boolean or float or str or list
            Refer to http://lxml.de/xpathxslt.html#xpath-return-values
        '''

        if 'namespaces' not in kwargs:
            kwargs['namespaces'] = {i[1]: i[2] for i in self.device.namespaces
                                    if i[1] is not None}
        return self.ele.xpath(*args, **kwargs)