remodel
Very simple yet powerful and extensible Object Document Mapper for RethinkDB, written in Python.
It is plain simple!
from remodel.models import Model
class User(Model):
passThat's really everything you need to do to set up a model!
Don't forget to turn on your RethinkDB server and to create your tables (check the examples below for a helper that does just that!).
Features
- schemaless;
dictinterface;- full support for relations;
- indexes;
- convention over configuration;
- lazy-loading;
- caching;
- thoroughly tested;
Installation
pip install remodelExamples
Basic CRUD operations
class Order(Model):
pass
# Create
my_order = Order.create(customer='Andrei', shop='GitHub')
# Update
my_order['total'] = 100
my_order.save()
# Read
saved_order = Order.get(customer='Andrei')
# Delete
saved_order.delete()Creating tables
from remodel.models import Model
from remodel.helpers import create_tables, create_indexes
class Party(Model):
has_many = ('Guest',)
class Guest(Model):
belongs_to = ('Party',)
# Creates all database tables defined by models
create_tables()
# Creates all table indexes based on model relations
create_indexes()Configuring database connection
Setups are widely different, so here's how you need to configure remodel in order to connect to your RethinkDB database:
from remodel.connection import pool
pool.configure(host='localhost', port=28015, auth_key=None, user='admin', password='', db='test')Relations
Has one / Belongs to
class User(Model):
has_one = ('Profile',)
class Profile(Model):
belongs_to = ('User',)
andrei = User.create(name='Andrei')
profile = Profile.create(user=andrei, network='GitHub', username='linkyndy')
print profile['user']['name'] # prints AndreiHas many / Belongs to
class Country(Model):
has_many = ('City',)
class City(Model):
belongs_to = ('Country',)
romania = Country.create(name='Romania')
romania['cities'].add(City(name='Timisoara'), City(name='Bucharest'))
print romania['cities'].count() # prints 2Has and belongs to many
class Post(Model):
has_and_belongs_to_many = ('Tag',)
class Tag(Model):
has_and_belongs_to_many = ('Post',)
my_post = Post.create(name='My first post')
personal_tag = Tag.create(name='personal')
public_tag = Tag.create(name='public')
my_post['tags'].add(personal_tag, public_tag)
print my_post['tags'].count() # prints 2Has many through
class Recipe(Model):
has_many = ('SpecificSpice',)
class Chef(Model):
has_many = ('SpecificSpice',)
class SpecificSpice(Model):
belongs_to = ('Recipe', 'Chef')
quattro_formaggi = Recipe.create(name='Pizza Quattro Formaggi')
andrei = Chef.create(name='Andrei')
andreis_special_quattro_formaggi = SpecificSpice.create(chef=andrei, recipe=quattro_formaggi, oregano=True, love=True)
print andreis_special_quatro_formaggi['love'] # prints TrueCallbacks
from remodel.models import Model
class Shirt(Model):
def after_init(self):
self.wash()
def wash(self):
print 'Gotta wash a shirt after creating it...'or
from remodel.models import Model, after_save
class Prize(Model):
@after_save
def brag(self):
print 'I just won a prize!'Custom table name
class Child(Model):
table_name = 'kids'
print Child.table_name # prints 'kids'Custom model queries
import rethinkdb as r
class Celebrity(Model):
pass
Celebrity.create(name='george clooney')
Celebrity.create(name='kate winslet')
upper = Celebrity.map({'name': r.row['name'].upcase()}).run()
print list(upper) # prints [{u'name': u'GEORGE CLOONEY'}, {u'name': u'KATE WINSLET'}]Custom instance methods
class Child(Model):
def is_minor(self):
if 'age' in self:
return self['age'] < 18
jack = Child.create(name='Jack', age=15)
jack.is_minor() # prints TrueCustom class methods
from remodel.object_handler import ObjectHandler, ObjectSet
class TripObjectHandler(ObjectHandler):
def in_europe(self):
return ObjectSet(self, self.query.filter({'continent': 'Europe'}))
class Trip(Model):
object_handler = TripObjectHandler
Trip.create(continent='Europe', city='Paris')
Trip.create(continent='Asia', city='Shanghai')
Trip.create(continent='Europe', city='Dublin')
print len(Trip.in_europe()) # prints 2Viewing object fields
class Train(Model):
pass
train = Train.create(nr=12345, destination='Paris', has_restaurant=True, classes=[1, 2])
print train.fields.as_dict()
# prints {u'classes': [1, 2], u'nr': 12345, u'destination': u'Paris', u'has_restaurant': True, u'id': u'd9b8d57f-5d67-4ff7-acf8-cbf7fdd65581'}Concepts
Relations
Remodel supports various types of relationships:
- has one
- belongs to
- has many
- has and belongs to many
- has many through
Defining relations
Related models are passed as tuples in a model's definition. All other aspects, such as foreign keys, indexes, lazy relation loading and relation cache are magically handled for you.
If you need precise definition for your related models, you can pass a configuration tuple instead of the string name of your related model:
class Artist(Model):
has_many = (('Song', 'songs', 'id', 'song_id'), 'Concert')
# Tuple definition: (<related model name>, <related objects accessor field>, <model key>, <related model key>)One important thing to notice is that reverse relationships are not automatically ensured if only one end of the relationship is defined. This means that if
Artist has_many Song,Song belongs_to Artistis not automatically enforced unless explicitly defined.
Using relations
Assigning has_one and belongs_to objects doesn't mean that they are persisted. You need to manually call save() on them; assuming Profile belongs_to User:
profile['user'] = User(...)
profile.save()On the other side, assigning has_many and has_and_belongs_to_many objects automatically persist them, so there is no need for you to call save() on them; assuming Shop has_many Product:
shop.add(product1, produt2)
# No need to call save() on products!Note that certain assignments of related objects can not be performed unless one (or both) of the objects is saved. You can not save a
GiftSizewith aGiftattached without saving theGiftobject first (when having aGiftSize belongs_to Gift).
Documentation
Can be found at https://github.com/linkyndy/remodel/wiki.
Motivation
The main reason for Remodel's existence was the need of a light-weight ODM for RethinkDB, one that doesn't force you to ensure a document schema, one that provides a familiar interface and one that gracefully handles relations between models.
Status
Remodel is under active development and it is not yet production-ready.
How to contribute?
Any contribution is highly appreciated! See CONTRIBUTING.md for more details.
License
See LICENSE