code: def download(source, sink=None):
      
      try:
          from urllib.request import urlretrieve  # Python 3
      except ImportError:
          from urllib import urlretrieve  # Python 2
      if sink is None:
          sink = os.path.abspath(os.path.split(source)[1])
      urlretrieve(source, sink)
      return sink
docs: Download a file.
  
      Parameters
      ----------
      source : str
          Where the file comes from. Some URL.
      sink : str or None (default: same filename in current directory)
          Where the file gets stored. Some filepath in the local file system.