[float] 获得该持仓的实时市场价值在股票投资组合价值中所占比例，取值范围[0, 1]

def value_percent(self):
        """
        [float] 获得该持仓的实时市场价值在股票投资组合价值中所占比例，取值范围[0, 1]
        """
        accounts = Environment.get_instance().portfolio.accounts
        if DEFAULT_ACCOUNT_TYPE.STOCK.name not in accounts:
            return 0
        total_value = accounts[DEFAULT_ACCOUNT_TYPE.STOCK.name].total_value
        return 0 if total_value == 0 else self.market_value / total_value