def pivot(self, attrlist):
        """Pivots the data using the given attributes, returning a L{PivotTable}.
            @param attrlist: list of attributes to be used to construct the pivot table
            @type attrlist: list of strings, or string of space-delimited attribute names
        """
        if isinstance(attrlist, basestring):
            attrlist = attrlist.split()
        if all(a in self._indexes for a in attrlist):
            return PivotTable(self, [], attrlist)
        else:
            raise ValueError("pivot can only be called using indexed attributes")