code: def main():
      args = parse_args()
      name = "Market-1501-v15.09.15"
      url = "http://apache-mxnet.s3-accelerate.dualstack.amazonaws.com/gluon/dataset/{name}.zip".format(
          name=name
      )
      root = osp.expanduser(args.download_dir)
      makedirs(root)
      fpath = osp.join(root, name + ".zip")
      exdir = osp.join(root, name)
      if (
          not osp.exists(fpath)
          and not osp.isdir(exdir)
          and args.no_download
      ):
          raise ValueError(
              (
                  "{} dataset archive not found, make sure it is present."
                  ' Or you should not disable "--no-download" to grab it'.format(
                      fpath
                  )
              )
          )
      # Download by default
      if not args.no_download:
          print("Downloading dataset")
          download(url, fpath, overwrite=False)
          print("Dataset downloaded")
      # Extract dataset if fresh copy downloaded or existing archive is yet to be extracted
      if not args.no_download or not osp.isdir(exdir):
          extract(fpath, root)
          make_list(exdir)
  
file_path: gluon-cv/scripts/datasets/market1501.py
imports: from __future__ import print_function, division
  import json
  import argparse
  from os import walk
  from os import path
  from zipfile import ZipFile
  from gluoncv.utils import download, makedirs
label_desc: Use image node_id 4 for calling a global function with example usage: main() without return types