docs: def translate_expression(expression):
      """
      Check if the expression is valid, then check turn it into an expression that can be used for filtering.
      :return list of lists: One or more matches. Each list has 3 strings.
      """
      logger_ts.info("enter translate_expression")
      m = re_filter_expr.findall(expression)
      matches = []
      if m:
          for i in m:
              logger_ts.info("parse match: {}".format(i))
              tmp = list(i[1:])
              if tmp[1] in COMPARISONS:
                  tmp[1] = COMPARISONS[tmp[1]]
              tmp[0] = cast_float(tmp[0])
              tmp[2] = cast_float(tmp[2])
              matches.append(tmp)
      else:
          logger_ts.warn("translate_expression: invalid expression: {}".format(expression))
          print("Invalid input expression")
      logger_ts.info("exit translate_expression")
      return matches