If you’re looking for lightweight and are already familiar with django-style declarative models, check out peewee:
https://github.com/coleifer/peewee
Example:
import datetime
from peewee import *
class Blog(Model):
name = CharField()
class Entry(Model):
blog = ForeignKeyField(Blog)
title = CharField()
body = TextField()
pub_date = DateTimeField(default=datetime.datetime.now)
# query it like django
Entry.filter(blog__name="Some great blog")
# or programmatically for finer-grained control
Entry.select().join(Blog).where(Blog.name == 'Some awesome blog')
Check the docs for more examples.