fudong1127 / peewee

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

peewee

Peewee is a simple and small ORM. It has few (but expressive) concepts, making it easy to learn and intuitive to use.

• 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
  • Postgresql HStore, JSON, arrays and more
  • SQLite full-text search, user-defined functions, virtual tables and more
  • Schema migrations and model code generator
  • Connection pool
  • Encryption
  • and much, much more...

New to peewee? Here is a list of documents you might find most helpful when getting started:

• Quickstart guide -- this guide covers all the essentials. It will take you between 5 and 10 minutes to go through it.
• Guide to the various query operators describes how to construct queries and combine expressions.
• Field types table lists the various field types peewee supports and the parameters they accept.

For flask helpers, check out the flask_utils extension module. You can also use peewee with the popular extension flask-admin to provide a Django-like admin interface for managing peewee models.

Examples

Defining models is similar to Django or SQLAlchemy:

from peewee import *
import datetime

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?

I've written a number of blog posts about building applications and web-services with peewee (and usually Flask). If you'd like to see some real-life applications that use peewee, the following resources may be useful:

• Building a note-taking app with Flask and Peewee as well as Part 2 and Part 3.
• Analytics web service built with Flask and Peewee.
• Personalized news digest (with a boolean query parser!).
• Using peewee to explore CSV files.
• Structuring Flask apps with Peewee.
• Creating a lastpass clone with Flask and Peewee.
• Building a web-based encrypted file manager with Flask, peewee and S3.
• Creating a bookmarking web-service that takes screenshots of your bookmarks.
• Building a pastebin, wiki and a bookmarking service using Flask and Peewee.
• Encrypted databases with Python and SQLCipher.
• Dear Diary: An Encrypted, Command-Line Diary with Peewee.
• Query Tree Structures in SQLite using Peewee and the Transitive Closure Extension.