dongo

A Django-ORM inspired Mongo ODM.

Python 2.7 and 3.x compatible, and requires the database server running at least MongoDB 2.6, as PyMongo does.

Installation

From PyPI::

$ pip install dongo

From the project root directory::

$ python setup.py install

Usage

Dongo is a Django-ORM inspired ODM for mongodb.

Here are a few examples of the query and class syntax.

Setup

You will need to first connect to a database and host. By default, localhost port 27017 will be selected, but you will still need to specify the default database::

from dongo import connect

# For the mydatabase named database on localhost
connect('mydatabase')

# For your mongodb in the private network
connect('mydatabase', host='192.168.1.200')

# For multiple hosts in a replica set
connect('mydatabase', hosts=['10.0.0.100', '10.0.0.101', '10.0.0.102:27018'], replica_set='myrepset0')

# A uri can explicitly be specified as well
connect('mydatabase', uri='mongodb://localhost:27017/')

You can separate collections into different databases, but those connections select the default database that collections will use if database is unspecified.

Next you will need to declare some sort of collection classes::

from dongo import DongoCollection
from datetime import datetime

class MusicArtist(DongoCollection):
    # if a specific database other than the default is desired, uncomment this:
    # database = 'myotherdatabase'
    collection = 'music_artists'

# That is all you need to query and read records from the collection "music_artists",
# and the following would create new records and insert them and query for them.

queen = MusicArtist({
    'name': 'queen',
    'lead': 'freddie',
    'songs': ['we are the champions', 'we will rock you'],
    'fans': ['jack', 'jill'],
    'nested': {
        'field1': 1,
        'field2': 2,
    },
})
# insert must be called manually
queen.insert()

# you can use keywords and auto-insert with the "new" classmethod.
queen_stoneage = MusicArtist.new(
    name='queens of the stone age',
    lead='josh',
    songs=['go with the flow', 'little sister'],
    start=datetime(year=1996, month=1, day=1),
    fans=['jack'],
    nested={
        'field1': 1,
        'field2': 222,
    },
)

# queries are simple
for ma in MusicArtist.filter(fans='jack'):
    print('jack likes ' + ma['name'])

# you can even do regex queries and bulk updates
MusicArtist.filter(name__regex='^queen').update(new_field='this is a new field')

# There are many operators, like __gt, __gte, __lt, __lte, __in, __nin, all corresponding to mongo's
# operators like $gt.

# you can do set logic as well with operators: |, &, ~
# for example less than comparisons and checking field existence:
for ma in (MusicArtist.filter(start__lt=datetime(2000, 1, 1)) | MusicArtist.filter(start__exists=0)):
    print('either this music artist started before the year 2000 or their startdate is unknown: ' + ma['name'])

# And you can query inside nested dictionaries

for ma in MusicArtist.filter(nested__field1=1):
    print(ma)

# updating the database or fetching fields is as easy as dictionary access
ma = MusicArtist.filter(name='queen').first()
ma['new_field'] = 'new_value'
print(ma['name'])
ma.set(new_field_2='a', new_field_3='b', new_field_4={'foo': 'bar'})
ma['nested.field1'] = 'new value in nested field'
ma.set(nested__field1='reset that nested field to this value')

You will likely want methods associated with records, and to do that you just extend your class definition::

class Person(DongoCollection):
    collection = 'persons'

    def print_name(self):
        print(self.get('name', 'unknown'))

    def serialize(self):
        return {
            'name': self.get('name'),
            'age': self.get('age', 0),
            'birthday': self.get('start', datetime.min).isoformat(),
            'favorite_color': self.get('color'),
        }

    def change_color(self, new_color):
        # updates record in database as well
        self['color'] = new_color

    @classmethod
    def start_new_year(cls):
        # add 1 to all age values for every record with a field "age"
        cls.filter(age__exists=1).inc(age=1)
        # kill off those 110 and older
        cls.filter(age__gte=110).delete()

    @classmethod
    def startswith(cls, prefix):
        # find all persons with a name that starts with ``prefix``
        regex = '^{}'.format(prefix)
        return cls.filter(name__regex=regex)

    @classmethod
    def endswith(cls, suffix):
        # find all persons with a name that ends with ``suffix``
        regex = '{}$'.format(suffix)
        return cls.filter(name__regex=regex)

    @classmethod
    def first_10(cls):
        return cls.filter().iter(limit=10, sort='name')

    @classmethod
    def sort_by_oldest_first_then_alphabetically(cls):
        return cls.filter().iter(sort=[('age', -1), ('name', 1)])

Release Notes

:0.4.0: Added DongoBulk functionality, with lazy and bulk operations. :0.3.0: Added Dongo references feature, with instance.ref() and deref :0.2.3: Removed unnecessary dependency :0.2.2: Released alpha with python 2.7 and 3.x compatibility :0.2.1: Released alpha with python 3.x compatibility