tortoise-orm 0.10.1

Easy async ORM for python, built with relations in mind

Introduction

Tortoise is easy-to-use asyncio ORM inspired by Django.

It is built with relations between models in mind and provides simple api for it, that gives you potential for building web services with easy abstractions.

You can find docs at readthedocs

Disclaimer

Tortoise is young project and breaking changes without following semantic versioning are to be expected

Installation

First you have to install tortoise like this:

pip install tortoise-orm

Then you should install your db driver

pip install asyncpg aiosqlite

Tutorial

Primary entity of tortoise is tortoise.models.Model. You can start writing models like this:

from tortoise.models import Model
from tortoise import fields

class Tournament(Model):
    id = fields.IntField(pk=True)
    name = fields.TextField()

    def __str__(self):
        return self.name


class Event(Model):
    id = fields.IntField(pk=True)
    name = fields.TextField()
    tournament = fields.ForeignKeyField('models.Tournament', related_name='events')
    participants = fields.ManyToManyField('models.Team', related_name='events', through='event_team')

    def __str__(self):
        return self.name


class Team(Model):
    id = fields.IntField(pk=True)
    name = fields.TextField()

    def __str__(self):
        return self.name

After you defined all your models, tortoise needs you to init them, in order to create backward relations between models and match your db client with appropriate models.

You can do it like this:

from tortoise import Tortoise
from tortoise.utils import generate_schema

async def init():
    # Here we connect to a PostgresQL DB
    # also specify the app name of "models"
    # which contain models from "app.models"
    await Tortoise.init(
        db_url='postgres://postgres:qwerty123@localhost:5432/events',
        modules={'models': ['app.models']}
    )
    # Generate the schema
    await Tortoise.generate_schemas()

Here we create connection to PostgresQL database with default asyncpg client and then we discover & initialise models.

generate_schema generates schema on empty database, you shouldn’t run it on every app init, run it just once, maybe out of your main code.

After that you can start using your models:

# Create instance by save
tournament = Tournament(name='New Tournament')
await tournament.save()

# Or by .create()
await Event.create(name='Without participants', tournament=tournament)
event = await Event.create(name='Test', tournament=tournament)
participants = []
for i in range(2):
    team = Team.create(name='Team {}'.format(i + 1))
    participants.append(team)

# M2M Relationship management is quite straightforward
# (also look for methods .remove(...) and .clear())
await event.participants.add(*participants)

# You can query related entity just with async for
async for team in event.participants:
    pass

# After making related query you can iterate with regular for,
# which can be extremely convenient for using with other packages,
# for example some kind of serializers with nested support
for team in event.participants:
    pass


# Or you can make preemptive call to fetch related objects
selected_events = await Event.filter(
    participants=participants[0].id
).prefetch_related('participants', 'tournament')

# Tortoise supports variable depth of prefetching related entities
# This will fetch all events for team and in those events tournaments will be prefetched
await Team.all().prefetch_related('events__tournament')

# You can filter and order by related models too
await Tournament.filter(
    events__name__in=['Test', 'Prod']
).order_by('-events__participants__name').distinct()

If you want to contribute check out issues, or just straightforwardly create PR