Fix urllib.error bad import (#120)

Author: shifucun

datacommons/query.py

@@ -104,9 +104,7 @@ def query(query_string, select=None):
   try:
     res = six.moves.urllib.request.urlopen(req)
   except six.moves.urllib.error.HTTPError as e:
-    raise ValueError(
-        'Response error: An HTTP {} code was returned by the mixer. Printing '
-        'response\n\n{}'.format(e.code, e.read()))
+    raise ValueError('Response error {}:\n{}'.format(e.code, e.read()))
 
   # Verify then store the results.
   res_json = json.loads(res.read())

datacommons/utils.py

@@ -106,7 +106,7 @@ def _send_request(req_url, req_json={}, compress=False, post=True):
     req = six.moves.urllib.request.Request(req_url, headers=headers)
   try:
     res = six.moves.urllib.request.urlopen(req)
-  except urllib.error.HTTPError as e:
+  except six.moves.urllib.error.HTTPError as e:
     raise ValueError(
         'Response error: An HTTP {} code was returned by the mixer. Printing '
         'response\n\n{}'.format(e.code, e.read()))