def get_positions(self, attr=None):
        """Get the positions data for the instrument

        :Optional:
            attr : string
                Position attribute to get
                (optional attributes: symbol, position, avgCost, account)

        :Retruns:
            positions : dict (positions) / float/str (attribute)
                positions data for the instrument
        """
        pos = self.parent.get_positions(self)
        try:
            if attr is not None:
                attr = attr.replace("quantity", "position")
            return pos[attr]
        except Exception as e:
            return pos