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
- python 2.7+ and 3.4+ (developed with 3.6)
- supports sqlite, mysql, postgresql and cockroachdb
- tons of extensions
Defining models is similar to Django or SQLAlchemy:
from peewee import * import datetime db = SqliteDatabase('my_database.db') class BaseModel(Model): class Meta: database = db class User(BaseModel): username = CharField(unique=True) class Tweet(BaseModel): user = ForeignKeyField(User, backref='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 == 'charlie') # Get tweets created by one of several users. usernames = ['charlie', 'huey', 'mickey'] users = User.select().where(User.username.in_(usernames)) tweets = Tweet.select().where(Tweet.user.in_(users)) # We could accomplish the same using a JOIN: tweets = (Tweet .select() .join(User) .where(User.username.in_(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 twitter app <http://docs.peewee-orm.com/en/latest/peewee/example.html>_.