def _getValues(self):
        try:
            with open(self.filename) as file:
                val = int(file.read())
                rval = val - self.bytes
                self.bytes = val
                return rval
        except __HOLE__:
            return 0
dataset/ETHPy150Open qtile/qtile/libqtile/widget/graph.py/NetGraph._getValues