我试图使用MNIST手写数字数据库，但下面两行给我错误。我哪里错了？
from sklearn import datasets
dataset = datasets.fetch_mldata('MNIST original')
我得到的错误如下：
Traceback (most recent call last):
File "E:/HWrecognition/deep-belief-network-gpu-update/kk.py", line 5, in <module>
dataset = datasets.fetch_mldata('MNIST original')
File "C:\Python27\lib\site-packages\sklearn\datasets\mldata.py", line 142, in fetch_mldata
mldata_url = urlopen(urlname)
File "C:\Python27\lib\urllib2.py", line 126, in urlopen
return _opener.open(url, data, timeout)
File "C:\Python27\lib\urllib2.py", line 397, in open
response = meth(req, response)
File "C:\Python27\lib\urllib2.py", line 510, in http_response
'http', request, response, code, msg, hdrs)
File "C:\Python27\lib\urllib2.py", line 429, in error
result = self._call_chain(*args)
File "C:\Python27\lib\urllib2.py", line 369, in _call_chain
result = func(*args)
File "C:\Python27\lib\urllib2.py", line 605, in http_error_302
return self.parent.open(new, timeout=req.timeout)
File "C:\Python27\lib\urllib2.py", line 391, in open
response = self._open(req, data)
File "C:\Python27\lib\urllib2.py", line 409, in _open
'_open', req)
File "C:\Python27\lib\urllib2.py", line 369, in _call_chain
result = func(*args)
File "C:\Python27\lib\urllib2.py", line 1173, in http_open
return self.do_open(httplib.HTTPConnection, req)
File "C:\Python27\lib\urllib2.py", line 1148, in do_open
raise URLError(err)
urllib2.URLError: <urlopen error [Errno 10109] getaddrinfo failed>