code: def available_ports(low=1024, high=65535, exclude_ranges=None):
      
      if exclude_ranges is None:
          exclude_ranges = []
      available = utils.ranges_to_set(UNASSIGNED_RANGES)
      exclude = utils.ranges_to_set(
          ephemeral.port_ranges() + exclude_ranges +
          [
              SYSTEM_PORT_RANGE,
              (SYSTEM_PORT_RANGE[1], low),
              (high, 65536)
          ]
      )
      return available.difference(exclude)
docs: Returns a set of possible ports (excluding system,
      ephemeral and well-known ports).
  
      Pass ``high`` and/or ``low`` to limit the port range.