Fix bug with null check in get_stats and get_property_values api (#127)

Author: shifucun

datacommons/core.py

@@ -178,10 +178,12 @@ def get_property_values(dcids,
   for dcid in dcids:
     # Get the list of nodes based on the direction given.
     nodes = []
-    if dcid in payload and out:
-      nodes = payload[dcid]['out']
-    elif dcid in payload and not out:
-      nodes = payload[dcid]['in']
+    if out:
+      if dcid in payload and 'out' in payload[dcid]:
+        nodes = payload[dcid]['out']
+    else:
+       if dcid in payload and 'in' in payload[dcid]:
+          nodes = payload[dcid]['in']
 
     # Add nodes to unique_results if it is not empty
     for node in nodes:

datacommons/examples/core.py

@@ -24,7 +24,7 @@
 
 def main():
   # Set the dcid to be that of Santa Clara County.
-  dcids = ['geoId/06085']
+  dcids = ['geoId/06085', 'dc/p/zsb968m3v1f97']
 
   # Print all incoming and outgoing properties from Santa Clara County.
   print('Property Labels for Santa Clara County')

datacommons/places.py

@@ -71,7 +71,7 @@ def get_places_in(dcids, place_type):
   # Create the results and format it appropriately
   result = utils._format_expand_payload(payload, 'place', must_exist=dcids)
   return result
-  
+
 def get_stats(dcids, stats_var, obs_dates='latest'):
   """ Returns :obj:`TimeSeries` for :code:`dcids` \
     based on the :code:`stats_var`.
@@ -119,7 +119,7 @@ def get_stats(dcids, stats_var, obs_dates='latest'):
       },
       'geoId/05': {
         'place_name': 'California'
-        'data': { 
+        'data': {
           '2011':316667,
           '2012':324116,
           '2013':331853,
@@ -146,6 +146,8 @@ def get_stats(dcids, stats_var, obs_dates='latest'):
       res.update(payload)
     elif obs_dates == 'latest':
       for geo, stats in payload.items():
+        if not stats:
+          continue
         time_series = stats.get('data')
         if not time_series: continue
         max_date = max(time_series)
@@ -156,6 +158,8 @@ def get_stats(dcids, stats_var, obs_dates='latest'):
     elif obs_dates:
       obs_dates = set(obs_dates)
       for geo, stats in payload.items():
+        if not stats:
+          continue
         time_series = stats.get('data')
         if not time_series: continue
         for date in list(time_series):

datacommons/test/core_test.py

@@ -155,6 +155,12 @@ def read(self):
         }
       })
       return MockResponse(json.dumps({'payload': res_json}))
+    if data['dcids'] == ['dc/p/1234'] and data['property'] == 'name':
+      # Response for sending a request for the name with no data
+      res_json = json.dumps({
+        'dc/p/1234': {}
+      })
+      return MockResponse(json.dumps({'payload': res_json}))
     if data['dcids'] == ['geoId/06085', 'geoId/24031']\
       and data['property'] == 'madProperty':
       # Response for sending a request with a property that does not exist.
@@ -427,6 +433,12 @@ def test_multiple_dcids(self, urlopen_mock):
       'geoId/24031': ['Montgomery County']
     })
 
+    # Return empty result when there is no data.
+    names = dc.get_property_values(['dc/p/1234'], 'name')
+    self.assertDictEqual(names, {
+      'dc/p/1234': []
+    })
+
   @mock.patch('urllib.request.urlopen', side_effect=request_mock)
   def test_bad_dcids(self, urlopen_mock):
     """ Calling get_property_values with dcids that do not exist returns empty

datacommons/test/places_test.py

@@ -26,7 +26,7 @@
 import datacommons.utils as utils
 import json
 import unittest
-import six.moves.urllib
+import six.moves.urllib as urllib
 
 
 def request_mock(*args, **kwargs):
@@ -122,7 +122,14 @@ def read(self):
           }
       })
       return MockResponse(json.dumps({'payload': res_json}))
-    if ((data['place'] == ['geoId/05', 'dc/MadDcid'] or 
+    if (data['place'] == ['geoId/00'] and
+        data['stats_var'] == 'dc/0hyp6tkn18vcb'):
+      # No data for the request
+      res_json = json.dumps({
+          'geoId/00': None
+      })
+      return MockResponse(json.dumps({'payload': res_json}))
+    if ((data['place'] == ['geoId/05', 'dc/MadDcid'] or
          data['place'] == ['geoId/05']) and
         data['stats_var'] == 'dc/0hyp6tkn18vcb'):
       # Response ignores dcid that does not exist.
@@ -355,6 +362,16 @@ def test_no_dcids(self, urlopen):
     no_dcids = dc.get_stats([], 'dc/0hyp6tkn18vcb')
     self.assertDictEqual({}, no_dcids)
 
+  @mock.patch('urllib.request.urlopen', side_effect=request_mock)
+  def test_no_data(self, urlopen):
+    """ Calling get_stats with for None data. """
+    # Set the API key
+    dc.set_api_key('TEST-API-KEY')
+
+    # Call get_stats with no dcids.
+    result = dc.get_stats(['geoId/00'], 'dc/0hyp6tkn18vcb')
+    self.assertDictEqual({}, result)
+
   @mock.patch('six.moves.urllib.request.urlopen', side_effect=request_mock)
   def test_batch_request(self, mock_urlopen):
     """ Make multiple calls to REST API when number of geos exceeds the batch size. """