# Simple Python script to download a file. Used as a fallback
# when other more reliable methods fail.
#
from __future__ import print_function
import sys

try:
 from requests import get
except ImportError:
 try:
 from urllib.request import urlretrieve
 USING = "urllib.request.urlretrieve"
 except ImportError:
 try:
 from urllib import urlretrieve
 USING = "urllib.retrieve"
 except ImportError:
 print("Python at", sys.executable, "is not suitable",
 "for downloading files.", file=sys.stderr)
 sys.exit(2)
else:
 USING = "requests.get"

 def urlretrieve(url, filename):
 r = get(url, stream=True)
 r.raise_for_status()
 with open(filename, 'wb') as f:
 for chunk in r.iter_content(chunk_size=1024):
 f.write(chunk)
 return filename

if __name__ == '__main__':
 if len(sys.argv) != 3:
 print("Usage: urlretrieve.py [url] [filename]", file=sys.stderr)
 sys.exit(1)
 URL = sys.argv[1]
 FILENAME = sys.argv[2]
 print("Downloading from", URL, "to", FILENAME, "using", USING)
 urlretrieve(URL, FILENAME)