Merge branch 'mapreduce' of git://github.com/blackbrrr/mongoengine
Conflicts: mongoengine/queryset.py
This commit is contained in:
Harry Marr
commit
047cc218a6
@ -21,6 +21,9 @@ Documents
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.. autoclass:: mongoengine.EmbeddedDocument
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:members:
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.. autoclass:: mongoengine.MapReduceDocument
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:members:
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Querying
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========
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@ -22,7 +22,7 @@ sys.path.append(os.path.abspath('..'))
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# Add any Sphinx extension module names here, as strings. They can be extensions
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# coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
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extensions = ['sphinx.ext.autodoc']
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extensions = ['sphinx.ext.autodoc', 'sphinx.ext.todo']
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# Add any paths that contain templates here, relative to this directory.
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templates_path = ['_templates']
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@ -115,3 +115,39 @@ class Document(BaseDocument):
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"""
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db = _get_db()
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db.drop_collection(cls._meta['collection'])
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class MapReduceDocument(object):
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"""A document returned from a map/reduce query.
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:param collection: An instance of :class:`~pymongo.Collection`
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:param key: Document/result key, often an instance of
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:class:`~pymongo.objectid.ObjectId`. If supplied as
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an ``ObjectId`` found in the given ``collection``,
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the object can be accessed via the ``object`` property.
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:param value: The result(s) for this key.
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.. versionadded:: 0.3
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"""
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def __init__(self, document, collection, key, value):
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self._document = document
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self._collection = collection
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self.key = key
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self.value = value
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@property
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def object(self):
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"""Lazy-load the object referenced by ``self.key``. If ``self.key``
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is not an ``ObjectId``, simply return ``self.key``.
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"""
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if not isinstance(self.key, (pymongo.objectid.ObjectId)):
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try:
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self.key = pymongo.objectid.ObjectId(self.key)
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except:
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return self.key
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if not hasattr(self, "_key_object"):
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self._key_object = self._document.objects.with_id(self.key)
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return self._key_object
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return self._key_object
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@ -30,6 +30,7 @@ class OperationError(Exception):
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RE_TYPE = type(re.compile(''))
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class Q(object):
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OR = '||'
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@ -143,6 +144,7 @@ class QuerySet(object):
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self._query = {}
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self._where_clause = None
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self._loaded_fields = []
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self._ordering = []
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# If inheritance is allowed, only return instances and instances of
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# subclasses of the class being used
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@ -360,7 +362,7 @@ class QuerySet(object):
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may be provided as a keyword argument called :attr:`defaults`.
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"""
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defaults = query.get('defaults', {})
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if query.has_key('defaults'):
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if 'defaults' in query:
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del query['defaults']
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self.__call__(*q_objs, **query)
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@ -439,6 +441,70 @@ class QuerySet(object):
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def __len__(self):
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return self.count()
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def map_reduce(self, map_f, reduce_f, finalize_f=None, limit=None,
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scope=None, keep_temp=False):
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"""Perform a map/reduce query using the current query spec
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and ordering. While ``map_reduce`` respects ``QuerySet`` chaining,
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it must be the last call made, as it does not return a maleable
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``QuerySet``.
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See the :meth:`~mongoengine.tests.QuerySetTest.test_map_reduce`
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and :meth:`~mongoengine.tests.QuerySetTest.test_map_advanced`
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tests in ``tests.queryset.QuerySetTest`` for usage examples.
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:param map_f: map function, as :class:`~pymongo.code.Code` or string
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:param reduce_f: reduce function, as
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:class:`~pymongo.code.Code` or string
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:param finalize_f: finalize function, an optional function that
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performs any post-reduction processing.
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:param scope: values to insert into map/reduce global scope. Optional.
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:param limit: number of objects from current query to provide
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to map/reduce method
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:param keep_temp: keep temporary table (boolean, default ``True``)
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Returns an iterator yielding
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:class:`~mongoengine.document.MapReduceDocument`.
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.. note:: Map/Reduce requires server version **>= 1.1.1**. The PyMongo
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:meth:`~pymongo.collection.Collection.map_reduce` helper requires
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PyMongo version **>= 1.2**.
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.. versionadded:: 0.3
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"""
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from document import MapReduceDocument
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if not hasattr(self._collection, "map_reduce"):
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raise NotImplementedError("Requires MongoDB >= 1.1.1")
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if not isinstance(map_f, pymongo.code.Code):
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map_f = pymongo.code.Code(map_f)
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if not isinstance(reduce_f, pymongo.code.Code):
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reduce_f = pymongo.code.Code(reduce_f)
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mr_args = {'query': self._query, 'keeptemp': keep_temp}
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if finalize_f:
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if not isinstance(finalize_f, pymongo.code.Code):
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finalize_f = pymongo.code.Code(finalize_f)
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mr_args['finalize'] = finalize_f
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if scope:
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mr_args['scope'] = scope
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if limit:
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mr_args['limit'] = limit
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results = self._collection.map_reduce(map_f, reduce_f, **mr_args)
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results = results.find()
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if self._ordering:
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results = results.sort(self._ordering)
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for doc in results:
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yield MapReduceDocument(self._document, self._collection,
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doc['_id'], doc['value'])
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def limit(self, n):
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"""Limit the number of returned documents to `n`. This may also be
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achieved using array-slicing syntax (e.g. ``User.objects[:5]``).
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@ -450,6 +516,7 @@ class QuerySet(object):
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else:
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self._cursor.limit(n)
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self._limit = n
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# Return self to allow chaining
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return self
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@ -525,6 +592,7 @@ class QuerySet(object):
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key = key[1:]
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key_list.append((key, direction))
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self._ordering = key_list
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self._cursor.sort(key_list)
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return self
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@ -836,6 +904,7 @@ class QuerySetManager(object):
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queryset = self._manager_func(owner, queryset)
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return queryset
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def queryset_manager(func):
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"""Decorator that allows you to define custom QuerySet managers on
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:class:`~mongoengine.Document` classes. The manager must be a function that
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@ -1,6 +1,9 @@
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# -*- coding: utf-8 -*-
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import unittest
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import pymongo
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from datetime import datetime
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from datetime import datetime, timedelta
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from mongoengine.queryset import (QuerySet, MultipleObjectsReturned,
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DoesNotExist)
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@ -631,6 +634,163 @@ class QuerySetTest(unittest.TestCase):
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ages = [p.age for p in self.Person.objects.order_by('-name')]
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self.assertEqual(ages, [30, 40, 20])
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def test_map_reduce(self):
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"""Ensure map/reduce is both mapping and reducing.
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"""
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class BlogPost(Document):
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title = StringField()
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tags = ListField(StringField())
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BlogPost.drop_collection()
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BlogPost(title="Post #1", tags=['music', 'film', 'print']).save()
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BlogPost(title="Post #2", tags=['music', 'film']).save()
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BlogPost(title="Post #3", tags=['film', 'photography']).save()
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map_f = """
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function() {
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this.tags.forEach(function(tag) {
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emit(tag, 1);
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});
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}
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"""
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reduce_f = """
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function(key, values) {
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var total = 0;
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for(var i=0; i<values.length; i++) {
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total += values[i];
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}
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return total;
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}
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"""
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# run a map/reduce operation spanning all posts
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results = BlogPost.objects.map_reduce(map_f, reduce_f)
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results = list(results)
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self.assertEqual(len(results), 4)
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music = filter(lambda r: r.key == "music", results)[0]
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self.assertEqual(music.value, 2)
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film = filter(lambda r: r.key == "film", results)[0]
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self.assertEqual(film.value, 3)
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BlogPost.drop_collection()
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def test_map_reduce_finalize(self):
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"""Ensure that map, reduce, and finalize run and introduce "scope"
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by simulating "hotness" ranking with Reddit algorithm.
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"""
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from time import mktime
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class Link(Document):
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title = StringField()
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up_votes = IntField()
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down_votes = IntField()
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submitted = DateTimeField()
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Link.drop_collection()
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now = datetime.utcnow()
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# Note: Test data taken from a custom Reddit homepage on
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# Fri, 12 Feb 2010 14:36:00 -0600. Link ordering should
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# reflect order of insertion below, but is not influenced
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# by insertion order.
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Link(title = "Google Buzz auto-followed a woman's abusive ex ...",
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up_votes = 1079,
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down_votes = 553,
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submitted = now-timedelta(hours=4)).save()
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Link(title = "We did it! Barbie is a computer engineer.",
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up_votes = 481,
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down_votes = 124,
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submitted = now-timedelta(hours=2)).save()
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Link(title = "This Is A Mosquito Getting Killed By A Laser",
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up_votes = 1446,
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down_votes = 530,
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submitted=now-timedelta(hours=13)).save()
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Link(title = "Arabic flashcards land physics student in jail.",
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up_votes = 215,
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down_votes = 105,
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submitted = now-timedelta(hours=6)).save()
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Link(title = "The Burger Lab: Presenting, the Flood Burger",
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up_votes = 48,
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down_votes = 17,
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submitted = now-timedelta(hours=5)).save()
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Link(title="How to see polarization with the naked eye",
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up_votes = 74,
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down_votes = 13,
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submitted = now-timedelta(hours=10)).save()
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map_f = """
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function() {
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emit(this._id, {up_delta: this.up_votes - this.down_votes,
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sub_date: this.submitted.getTime() / 1000})
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}
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"""
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reduce_f = """
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function(key, values) {
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data = values[0];
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x = data.up_delta;
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// calculate time diff between reddit epoch and submission
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sec_since_epoch = data.sub_date - reddit_epoch;
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// calculate 'Y'
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if(x > 0) {
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y = 1;
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} else if (x = 0) {
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y = 0;
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} else {
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y = -1;
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}
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// calculate 'Z', the maximal value
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if(Math.abs(x) >= 1) {
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z = Math.abs(x);
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} else {
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z = 1;
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}
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return {x: x, y: y, z: z, t_s: sec_since_epoch};
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}
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"""
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finalize_f = """
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function(key, value) {
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// f(sec_since_epoch,y,z) = log10(z) + ((y*sec_since_epoch) / 45000)
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z_10 = Math.log(value.z) / Math.log(10);
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weight = z_10 + ((value.y * value.t_s) / 45000);
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return weight;
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}
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"""
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# provide the reddit epoch (used for ranking) as a variable available
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# to all phases of the map/reduce operation: map, reduce, and finalize.
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reddit_epoch = mktime(datetime(2005, 12, 8, 7, 46, 43).timetuple())
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scope = {'reddit_epoch': reddit_epoch}
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# run a map/reduce operation across all links. ordering is set
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# to "-value", which orders the "weight" value returned from
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# "finalize_f" in descending order.
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results = Link.objects.order_by("-value")
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results = results.map_reduce(map_f,
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reduce_f,
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finalize_f=finalize_f,
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scope=scope)
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results = list(results)
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# assert troublesome Buzz article is ranked 1st
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self.assertTrue(results[0].object.title.startswith("Google Buzz"))
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# assert laser vision is ranked last
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self.assertTrue(results[-1].object.title.startswith("How to see"))
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Link.drop_collection()
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def test_item_frequencies(self):
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"""Ensure that item frequencies are properly generated from lists.
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"""
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