code: def get_account(self, portfolio_cookie: str, account_cookie: str):
          
  
          try:
              return self.portfolio_list[portfolio_cookie][account_cookie]
          except:
              return None
docs: 直接从二级目录拿到account
  
          Arguments:
              portfolio_cookie {str} -- [description]
              account_cookie {str} -- [description]
  
          Returns:
              [type] -- [description]