def _FindHDDSerial(self):
    """Find the primary Hard Drive Disk serial number."""
    disk_items = (self._GetDataTypeItems('serialata') +
                  self._GetDataTypeItems('parallelata') -
                  self._GetDataTypeItems('nvme'))
    for disk_item in disk_items:
      for item in disk_item['_items']:
        if 'device_serial' in item:
          self._profile['hdd_serial'] = item['device_serial'].strip()
          return
dataset/ETHPy150Open google/simian/src/simian/mac/common/hw.py/SystemProfile._FindHDDSerial/operator `+` -> `-`