text: import os
  import os.path as osp
  import time
  import shutil
  import torch
  import torchvision
  import torch.nn.parallel
  import torch.backends.cudnn as cudnn
  import torch.nn.functional as F
  import torch.optim
  import cv2
  import numpy as np
  import models
  import argparse
  from utils.config import Config
  from runner.runner import Runner 
  from datasets import build_dataloader
  
  
  def main():
      args = parse_args()
      os.environ["CUDA_VISIBLE_DEVICES"] = ','.join(str(gpu) for gpu in args.gpus)
  
      cfg = Config.fromfile(args.config)
      cfg.gpus = len(args.gpus)
  
      cfg.load_from = args.load_from
      cfg.finetune_from = args.finetune_from
      cfg.view = args.view
  
      cfg.work_dirs = args.work_dirs + '/' + cfg.dataset.train.type
  
      cudnn.benchmark = True
      cudnn.fastest = True
  
      runner = Runner(cfg)
  
      if args.validate:
          val_loader = build_dataloader(cfg.dataset.val, cfg, is_train=False)
          runner.validate(val_loader)
      else:
          runner.train()
  
  def parse_args():
      parser = argparse.ArgumentParser(description='Train a detector')
      parser.add_argument('config', help='train config file path')
      parser.add_argument(
          '--work_dirs', type=str, default='work_dirs',
          help='work dirs')
      parser.add_argument(
          '--load_from', default=None,
          help='the checkpoint file to resume from')
      parser.add_argument(
          '--finetune_from', default=None,
          help='whether to finetune from the checkpoint')
      parser.add_argument(
          '--validate',
          action='store_true',
          help='whether to evaluate the checkpoint during training')
      parser.add_argument(
          '--view',
          action='store_true',
          help='whether to show visualization result')
      parser.add_argument('--gpus', nargs='+', type=int, default='0')
      parser.add_argument('--seed', type=int,
                          default=None, help='random seed')
      args = parser.parse_args()
  
      return args
  
  
  if __name__ == '__main__':
      main()
  