code: def search(self, text, limit=1000, order_by=None, sort_order=None, filter=None):
          
          url = "%s/series/search?search_text=%s&" % (self.root_url,
                                                      quote_plus(text))
          info = self.__get_search_results(url, limit, order_by, sort_order, filter)
          return info
docs: Do a fulltext search for series in the Fred dataset. Returns information about matching series in a DataFrame.
  
          Parameters
          ----------
          text : str
              text to do fulltext search on, e.g., 'Real GDP'
          limit : int, optional
              limit the number of results to this value. If limit is 0, it means fetching all results without limit.
          order_by : str, optional
              order the results by a criterion. Valid options are 'search_rank', 'series_id', 'title', 'units', 'frequency',
              'seasonal_adjustment', 'realtime_start', 'realtime_end', 'last_updated', 'observation_start', 'observation_end',
              'popularity'
          sort_order : str, optional
              sort the results by ascending or descending order. Valid options are 'asc' or 'desc'
          filter : tuple, optional
              filters the results. Expects a tuple like (filter_variable, filter_value).
              Valid filter_variable values are 'frequency', 'units', and 'seasonal_adjustment'
  
          Returns
          -------
          info : DataFrame
              a DataFrame containing information about the matching Fred series