1  # Simple Python script to download a file. Used as a fallback
       2  # when other more reliable methods fail.
       3  #
       4  from __future__ import print_function
       5  import sys
       6  
       7  try:
       8      from requests import get
       9  except ImportError:
      10      try:
      11          from urllib.request import urlretrieve
      12          USING = "urllib.request.urlretrieve"
      13      except ImportError:
      14          try:
      15              from urllib import urlretrieve
      16              USING = "urllib.retrieve"
      17          except ImportError:
      18              print("Python at", sys.executable, "is not suitable",
      19                    "for downloading files.", file=sys.stderr)
      20              sys.exit(2)
      21  else:
      22      USING = "requests.get"
      23  
      24      def urlretrieve(url, filename):
      25          r = get(url, stream=True)
      26          r.raise_for_status()
      27          with open(filename, 'wb') as f:
      28              for chunk in r.iter_content(chunk_size=1024):
      29                  f.write(chunk)
      30          return filename
      31  
      32  if __name__ == '__main__':
      33      if len(sys.argv) != 3:
      34          print("Usage: urlretrieve.py [url] [filename]", file=sys.stderr)
      35          sys.exit(1)
      36      URL = sys.argv[1]
      37      FILENAME = sys.argv[2]
      38      print("Downloading from", URL, "to", FILENAME, "using", USING)
      39      urlretrieve(URL, FILENAME)