code: def company_category(self, symbol=''):
          '''
          查询公司信息目录
  
          :param market: 市场代码
          :param symbol: 股票代码
          :return: pd.dataFrame or None
          '''
          market = get_stock_market(symbol)
  
          with self.client.connect(*self.bestip):
              data = self.client.get_company_info_category(int(market), symbol)
              return self.client.to_df(dataf company_category(self, symbol=''):
          '''
          查询公司信息目录
  
          :param market: 市场代码
          :param symbol: 股票代码
          :return: pd.dataFrame or None
          '''
          market = get_stock_market(symbol)
  
          with self.client.connect(*self.bestip):
              data = self.client.get_company_info_category(int(market), symbol)
              return self.client.to_df(data)
docs: 查询公司信息目录
  
          :param market: 市场代码
          :param symbol: 股票代码
          :return: pd.dataFrame or None