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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 attr(self, *args):
        '''Add the specific attribute to the attribute dictionary
        with key ``name`` and value ``value`` and return ``self``.'''
        attr = self._attr
        if not args:
            return attr or {}
        result, adding = self._attrdata('attr', *args)
        if adding:
            for key, value in result.items():
                if DATARE.match(key):
                    self.data(key[5:], value)
                else:
                    if attr is None:
                        self._extra['attr'] = attr = {}
                    attr[key] = value
            result = self
        return result