wwj718/peewee

a small, expressive orm -- supports postgresql, mysql and sqlite

peewee

• A small, expressive ORM
• Written in python with support for versions 2.6+ and 3.2+.
• built-in support for sqlite, mysql and postgresql
• tons of extensions available in the playhouse (postgres hstore/json/arrays, sqlite full-text-search, schema migrations, and much more).

For flask integration, check out flask-peewee, which includes and admin interface, RESTful APIs, authentication, and more. You can also use peewee with the popular extension flask-admin.

Defining models is similar to Django or SQLAlchemy:

from peewee import *

db = SqliteDatabase('my_database.db', threadlocals=True)

class BaseModel(Model):
    class Meta:
        database = db

class User(BaseModel):
    username = CharField(unique=True)

class Tweet(BaseModel):
    user = ForeignKeyField(User, related_name='tweets')
    message = TextField()
    created_date = DateTimeField(default=datetime.datetime.now)
    is_published = BooleanField(default=True)

Connect to the database and create tables:

db.connect()
db.create_tables([User, Tweet])

Create a few rows:

charlie = User.create(username='charlie')
huey = User(username='huey')
huey.save()

# No need to set `is_published` or `created_date` since they
# will just use the default values we specified.
Tweet.create(user=charlie, message='My first tweet')

Queries are expressive and composable:

# A simple query selecting a user.
User.get(User.username == 'charles')

# Get tweets created by one of several users. The "<<" operator
# corresponds to the SQL "IN" operator.
usernames = ['charlie', 'huey', 'mickey']
users = User.select().where(User.username << usernames)
tweets = Tweet.select().where(Tweet.user << users)

# We could accomplish the same using a JOIN:
tweets = (Tweet
          .select()
          .join(User)
          .where(User.username << usernames))

# How many tweets were published today?
tweets_today = (Tweet
                .select()
                .where(
                    (Tweet.created_date >= datetime.date.today()) &
                    (Tweet.is_published == True))
                .count())

# Paginate the user table and show me page 3 (users 41-60).
User.select().order_by(User.username).paginate(3, 20)

# Order users by the number of tweets they've created:
tweet_ct = fn.Count(Tweet.id)
users = (User
         .select(User, tweet_ct.alias('ct'))
         .join(Tweet, JOIN_LEFT_OUTER)
         .group_by(User)
         .order_by(tweet_ct.desc()))

# Do an atomic update
Counter.update(count=Counter.count + 1).where(
    Counter.url == request.url)

Check out the example app for a working Twitter-clone website written with Flask.

Learning more

Check the documentation for more examples.

Specific question? Come hang out in the #peewee channel on freenode.irc.net, or post to the mailing list, http://groups.google.com/group/peewee-orm . If you would like to report a bug, create a new issue on GitHub.

Still want more info?

Why does peewee exist?

peewee began when I was working on a small app in flask and found myself writing lots of queries and wanting a very simple abstraction on top of the sql. I had so much fun working on it that I kept adding features. peewee is small enough that its my hope anyone with an interest in orms will be able to understand the code without much trouble.

I hope you enjoy using peewee as much as I've enjoyed working on it!