code: def get_gpu_count() -> int:
      """
      利用命令行获取 ``gpu`` 数目的函数
  
      :return: 显卡数目，如果没有显卡设备则为-1
      """
      try:
          lines = subprocess.check_output(
              ["nvidia-smi", "--query-gpu=memory.used", "--format=csv"]
          )
          # 经分割后还要除去头部和尾部的换行符
          return len(lines.split(b"\n")) - 2
      except:
          return -1
  
file_path: fastNLP/fastNLP/envs/utils.py
imports: import os
  import math
  import time
  from importlib.util import find_spec
  from typing import Callable
  import importlib
  from pkg_resources import DistributionNotFound
  from packaging.version import Version
  import subprocess
  import pkg_resources
label_desc: Use image node_id 4 for calling a global function with example usage: get_gpu_count() and returns: unknown, unknown