Overview

peewee is a lightweight ORM written in python.

Examples:

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

# get the staff and super users
editors = User.select().where(Q(is_staff=True) | Q(is_superuser=True))

# get tweets by editors
Tweet.select().where(user__in=editors)

# how many active users are there?
User.select().where(active=True).count()

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

# order users by number of tweets
User.select().annotate(Tweet).order_by(('count', 'desc'))

# another way of expressing the same
User.select({
    User: ['*'],
    Tweet: [Count('id', 'count')]
}).group_by('id').join(Tweet).order_by(('count', 'desc'))

# do an atomic update
TweetCount.update(count=F('count') + 1).where(user=charlie)

You can use django-style syntax to create select queries:

# how many active users are there?
User.filter(active=True).count()

# get tweets by a specific user
Tweet.filter(user__username='charlie')

# get tweets by editors
Tweet.filter(Q(user__is_staff=True) | Q(user__is_superuser=True))

Why?

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. My goal has always been, though, to keep the implementation incredibly simple. I’ve made a couple dives into django’s orm but have never come away with a deep understanding of its implementation. peewee is small enough that its my hope anyone with an interest in orms will be able to understand the code without too much trouble.