code: def filter_trends(self, pattern=''):
          
          filtered_trends = {}
          with open(self.abspath) as fobj:
              for idx, line in enumerate(fobj):
                  variable_idx = idx-self._attributes['CATALOG']-1
                  if 'TIME SERIES' in line:
                      break
                  if pattern in line and variable_idx > 0:
                      filtered_trends[variable_idx] = line
          return filtered_trends
docs: Filter available trends