with open("arxiv_2010_to_2016.json") as  f:
    X = json.load(f)

for article_id in X:
        link = X[article_id]["link"] + ".pdf"
        wget.download(link, out="docs")

File "/home/imane/anaconda3/lib/python3.6/site-packages/wget.py", line 526, in download
    (tmpfile, headers) = ulib.urlretrieve(binurl, tmpfile, callback)
  File "/home/imane/anaconda3/lib/python3.6/urllib/request.py", line 248, in urlretrieve
    with contextlib.closing(urlopen(url, data)) as fp:
  File "/home/imane/anaconda3/lib/python3.6/urllib/request.py", line 223, in urlopen
    return opener.open(url, data, timeout)
  File "/home/imane/anaconda3/lib/python3.6/urllib/request.py", line 532, in open
    response = meth(req, response)
  File "/home/imane/anaconda3/lib/python3.6/urllib/request.py", line 642, in http_response
    'http', request, response, code, msg, hdrs)
  File "/home/imane/anaconda3/lib/python3.6/urllib/request.py", line 564, in error
    result = self._call_chain(*args)
  File "/home/imane/anaconda3/lib/python3.6/urllib/request.py", line 504, in _call_chain
    result = func(*args)
  File "/home/imane/anaconda3/lib/python3.6/urllib/request.py", line 756, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File "/home/imane/anaconda3/lib/python3.6/urllib/request.py", line 532, in open
    response = meth(req, response)
  File "/home/imane/anaconda3/lib/python3.6/urllib/request.py", line 642, in http_response
    'http', request, response, code, msg, hdrs)
  File "/home/imane/anaconda3/lib/python3.6/urllib/request.py", line 570, in error
    return self._call_chain(*args)
  File "/home/imane/anaconda3/lib/python3.6/urllib/request.py", line 504, in _call_chain
    result = func(*args)
  File "/home/imane/anaconda3/lib/python3.6/urllib/request.py", line 650, in http_error_default
    raise HTTPError(req.full_url, code, msg, hdrs, fp)
urllib.error.HTTPError: HTTP Error 403: Forbidden