Added support for null / zero / false values in item_frequencies

refs /MongoEngine/mongoengine#40

docs/changelog.rst

@@ -4,6 +4,7 @@ Changelog
 
 Changes in 0.6.15
 =================
+- Added support for null / zero / false values in item_frequencies
 - Fixed cascade save edge case
 - Fixed geo index creation through reference fields
 - Added support for args / kwargs when using @queryset_manager

mongoengine/queryset.py

@@ -1718,10 +1718,11 @@ class QuerySet(object):
     def _item_frequencies_map_reduce(self, field, normalize=False):
         map_func = """
             function() {
-                path = '{{~%(field)s}}'.split('.');
-                field = this;
+                var path = '{{~%(field)s}}'.split('.');
+                var field = this;
+
                 for (p in path) {
-                    if (field)
+                    if (typeof field != 'undefined')
                        field = field[path[p]];
                     else
                        break;
@@ -1730,7 +1731,7 @@ class QuerySet(object):
                     field.forEach(function(item) {
                         emit(item, 1);
                     });
-                } else if (field) {
+                } else if (typeof field != 'undefined') {
                     emit(field, 1);
                 } else {
                     emit(null, 1);
@@ -1754,12 +1755,12 @@ class QuerySet(object):
             if isinstance(key, float):
                 if int(key) == key:
                     key = int(key)
-                key = str(key)
-            frequencies[key] = f.value
+            frequencies[key] = int(f.value)
 
         if normalize:
             count = sum(frequencies.values())
-            frequencies = dict([(k, v / count) for k, v in frequencies.items()])
+            frequencies = dict([(k, float(v) / count)
+                                for k, v in frequencies.items()])
 
         return frequencies
 
@@ -1767,12 +1768,11 @@ class QuerySet(object):
         """Uses exec_js to execute"""
         freq_func = """
             function(path) {
-                path = path.split('.');
+                var path = path.split('.');
 
-                if (options.normalize) {
                 var total = 0.0;
                 db[collection].find(query).forEach(function(doc) {
-                        field = doc;
+                    var field = doc;
                     for (p in path) {
                         if (field)
                             field = field[path[p]];
@@ -1785,13 +1785,11 @@ class QuerySet(object):
                        total++;
                     }
                 });
-                }
 
                 var frequencies = {};
+                var types = {};
                 var inc = 1.0;
-                if (options.normalize) {
-                    inc /= total;
-                }
+
                 db[collection].find(query).forEach(function(doc) {
                     field = doc;
                     for (p in path) {
@@ -1806,17 +1804,28 @@ class QuerySet(object):
                         });
                     } else {
                         var item = field;
+                        types[item] = item;
                         frequencies[item] = inc + (isNaN(frequencies[item]) ? 0: frequencies[item]);
                     }
                 });
-                return frequencies;
+                return [total, frequencies, types];
             }
         """
-        data = self.exec_js(freq_func, field, normalize=normalize)
-        if 'undefined' in data:
-            data[None] = data['undefined']
-            del(data['undefined'])
-        return data
+        total, data, types = self.exec_js(freq_func, field)
+        values = dict([(types.get(k), int(v)) for k, v in data.iteritems()])
+
+        if normalize:
+            values = dict([(k, float(v) / total) for k, v in values.items()])
+
+        frequencies = {}
+        for k, v in values.iteritems():
+            if isinstance(k, float):
+                if int(k) == k:
+                    k = int(k)
+
+            frequencies[k] = v
+
+        return frequencies
 
     def __repr__(self):
         """Provides the string representation of the QuerySet

tests/test_queryset.py

@@ -1994,9 +1994,9 @@ class QuerySetTest(unittest.TestCase):
 
         # Check item_frequencies works for non-list fields
         def test_assertions(f):
-            self.assertEqual(set(['1', '2']), set(f.keys()))
-            self.assertEqual(f['1'], 1)
-            self.assertEqual(f['2'], 2)
+            self.assertEqual(set([1, 2]), set(f.keys()))
+            self.assertEqual(f[1], 1)
+            self.assertEqual(f[2], 2)
 
         exec_js = BlogPost.objects.item_frequencies('hits')
         map_reduce = BlogPost.objects.item_frequencies('hits', map_reduce=True)
@@ -2096,7 +2096,6 @@ class QuerySetTest(unittest.TestCase):
             data = EmbeddedDocumentField(Data, required=True)
             extra = EmbeddedDocumentField(Extra)
 
-
         Person.drop_collection()
 
         p = Person()
@@ -2114,6 +2113,52 @@ class QuerySetTest(unittest.TestCase):
         ot = Person.objects.item_frequencies('extra.tag', map_reduce=True)
         self.assertEquals(ot, {None: 1.0, u'friend': 1.0})
 
+    def test_item_frequencies_with_0_values(self):
+        class Test(Document):
+            val = IntField()
+
+        Test.drop_collection()
+        t = Test()
+        t.val = 0
+        t.save()
+
+        ot = Test.objects.item_frequencies('val', map_reduce=True)
+        self.assertEquals(ot, {0: 1})
+        ot = Test.objects.item_frequencies('val', map_reduce=False)
+        self.assertEquals(ot, {0: 1})
+
+    def test_item_frequencies_with_False_values(self):
+        class Test(Document):
+            val = BooleanField()
+
+        Test.drop_collection()
+        t = Test()
+        t.val = False
+        t.save()
+
+        ot = Test.objects.item_frequencies('val', map_reduce=True)
+        self.assertEquals(ot, {False: 1})
+        ot = Test.objects.item_frequencies('val', map_reduce=False)
+        self.assertEquals(ot, {False: 1})
+
+    def test_item_frequencies_normalize(self):
+        class Test(Document):
+            val = IntField()
+
+        Test.drop_collection()
+
+        for i in xrange(50):
+            Test(val=1).save()
+
+        for i in xrange(20):
+            Test(val=2).save()
+
+        freqs = Test.objects.item_frequencies('val', map_reduce=False, normalize=True)
+        self.assertEquals(freqs, {1: 50.0/70, 2: 20.0/70})
+
+        freqs = Test.objects.item_frequencies('val', map_reduce=True, normalize=True)
+        self.assertEquals(freqs, {1: 50.0/70, 2: 20.0/70})
+
     def test_average(self):
         """Ensure that field can be averaged correctly.
         """