text: """Prepare MS COCO datasets"""
  import os
  import sys
  import argparse
  import zipfile
  
  # TODO: optim code
  cur_path = os.path.abspath(os.path.dirname(__file__))
  root_path = os.path.split(os.path.split(os.path.split(cur_path)[0])[0])[0]
  sys.path.append(root_path)
  
  from segmentron.utils import download, makedirs
  
  _TARGET_DIR = os.path.expanduser('~/.torch/datasets/coco')
  
  
  def parse_args():
      parser = argparse.ArgumentParser(
          description='Initialize MS COCO dataset.',
          epilog='Example: python mscoco.py --download-dir ~/mscoco',
          formatter_class=argparse.ArgumentDefaultsHelpFormatter)
      parser.add_argument('--download-dir', type=str, default=None, help='dataset directory on disk')
      parser.add_argument('--no-download', action='store_true', help='disable automatic download if set')
      parser.add_argument('--overwrite', action='store_true',
                          help='overwrite downloaded files if set, in case they are corrupted')
      args = parser.parse_args()
      return args
  
  
  def download_coco(path, overwrite=False):
      _DOWNLOAD_URLS = [
          # ('http://images.cocodataset.org/zips/train2017.zip',
          #  '10ad623668ab00c62c096f0ed636d6aff41faca5'),
          ('http://images.cocodataset.org/annotations/annotations_trainval2017.zip',
           '8551ee4bb5860311e79dace7e79cb91e432e78b3'),
          # ('http://images.cocodataset.org/zips/val2017.zip',
          #  '4950dc9d00dbe1c933ee0170f5797584351d2a41'),
          # ('http://images.cocodataset.org/annotations/stuff_annotations_trainval2017.zip',
          # '46cdcf715b6b4f67e980b529534e79c2edffe084'),
          # test2017.zip, for those who want to attend the competition.
          # ('http://images.cocodataset.org/zips/test2017.zip',
          #  '4e443f8a2eca6b1dac8a6c57641b67dd40621a49'),
      ]
      makedirs(path)
      for url, checksum in _DOWNLOAD_URLS:
          filename = download(url, path=path, overwrite=overwrite, sha1_hash=checksum)
          # extract
          with zipfile.ZipFile(filename) as zf:
              zf.extractall(path=path)
  
  
  if __name__ == '__main__':
      args = parse_args()
      default_dir = os.path.join(root_path, 'datasets/coco')
      if args.download_dir is not None:
          path = args.download_dir
      else:
          path = default_dir
      if not os.path.isdir(path) or not os.path.isdir(os.path.join(path, 'train2017')) \
              or not os.path.isdir(os.path.join(path, 'val2017')) \
              or not os.path.isdir(os.path.join(path, 'annotations')):
          if args.no_download:
              raise ValueError(('{} is not a valid directory, make sure it is present.'
                                ' Or you should not disable "--no-download" to grab it'.format(path)))
          else:
              download_coco(path, overwrite=args.overwrite)
  
      # make symlink
      try:
          os.symlink(path, default_dir)
      except Exception as e:
          print(e)
  