pub/mongoengine
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

QuerySet.item_frequencies works with non-list fields

Browse Source
This commit is contained in:
Harry Marr 2010-10-03 15:01:45 +01:00
parent 4c68bc6c96
commit 4012722a8d
2 changed files with 28 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
mongoengine/queryset.py
View File

@ -916,20 +916,27 @@ class QuerySet(object):
"""
return self.exec_js(average_func, field)
def item_frequencies(self, list_field, normalize=False):
"""Returns a dictionary of all items present in a list field across
def item_frequencies(self, field, normalize=False):
"""Returns a dictionary of all items present in a field across
the whole queried set of documents, and their corresponding frequency.
This is useful for generating tag clouds, or searching documents.
:param list_field: the list field to use
If the field is a :class:`~mongoengine.ListField`, the items within
each list will be counted individually.
:param field: the field to use
:param normalize: normalize the results so they add to 1.0
"""
freq_func = """
function(listField) {
function(field) {
if (options.normalize) {
var total = 0.0;
db[collection].find(query).forEach(function(doc) {
total += doc[listField].length;
if (doc[field].constructor == Array) {
total += doc[field].length;
} else {
total++;
}
});
}
@ -939,14 +946,19 @@ class QuerySet(object):
inc /= total;
}
db[collection].find(query).forEach(function(doc) {
doc[listField].forEach(function(item) {
if (doc[field].constructor == Array) {
doc[field].forEach(function(item) {
frequencies[item] = inc + (frequencies[item] || 0);
});
} else {
var item = doc[field];
frequencies[item] = inc + (frequencies[item] || 0);
});
}
});
return frequencies;
}
"""
return self.exec_js(freq_func, list_field, normalize=normalize)
return self.exec_js(freq_func, field, normalize=normalize)
def __repr__(self):
limit = REPR_OUTPUT_SIZE + 1

9
tests/queryset.py
View File

@ -973,7 +973,7 @@ class QuerySetTest(unittest.TestCase):
BlogPost(hits=1, tags=['music', 'film', 'actors']).save()
BlogPost(hits=2, tags=['music']).save()
BlogPost(hits=3, tags=['music', 'actors']).save()
BlogPost(hits=2, tags=['music', 'actors']).save()
f = BlogPost.objects.item_frequencies('tags')
f = dict((key, int(val)) for key, val in f.items())
@ -995,6 +995,13 @@ class QuerySetTest(unittest.TestCase):
self.assertAlmostEqual(f['actors'], 2.0/6.0)
self.assertAlmostEqual(f['film'], 1.0/6.0)
# Check item_frequencies works for non-list fields
f = BlogPost.objects.item_frequencies('hits')
f = dict((key, int(val)) for key, val in f.items())
self.assertEqual(set(['1', '2']), set(f.keys()))
self.assertEqual(f['1'], 1)
self.assertEqual(f['2'], 2)
BlogPost.drop_collection()
def test_average(self):