cqlengine is a Cassandra CQL 3 Object Mapper for Python
Users of versions < 0.16, the default keyspace 'cqlengine' has been removed. Please read this before upgrading: Breaking Changes
pip install cqlengine
#first, define a model
import uuid
from cqlengine import columns
from cqlengine.models import Model
class ExampleModel(Model):
read_repair_chance = 0.05 # optional - defaults to 0.1
example_id = columns.UUID(primary_key=True, default=uuid.uuid4)
example_type = columns.Integer(index=True)
created_at = columns.DateTime()
description = columns.Text(required=False)
#next, setup the connection to your cassandra server(s) and the default keyspace...
>>> from cqlengine import connection
>>> connection.setup(['127.0.0.1'], "cqlengine")
# or if you're still on cassandra 1.2
>>> connection.setup(['127.0.0.1'], "cqlengine", protocol_version=1)
#...and create your CQL table
>>> from cqlengine.management import sync_table
>>> sync_table(ExampleModel)
#now we can create some rows:
>>> em1 = ExampleModel.create(example_type=0, description="example1", created_at=datetime.now())
>>> em2 = ExampleModel.create(example_type=0, description="example2", created_at=datetime.now())
>>> em3 = ExampleModel.create(example_type=0, description="example3", created_at=datetime.now())
>>> em4 = ExampleModel.create(example_type=0, description="example4", created_at=datetime.now())
>>> em5 = ExampleModel.create(example_type=1, description="example5", created_at=datetime.now())
>>> em6 = ExampleModel.create(example_type=1, description="example6", created_at=datetime.now())
>>> em7 = ExampleModel.create(example_type=1, description="example7", created_at=datetime.now())
>>> em8 = ExampleModel.create(example_type=1, description="example8", created_at=datetime.now())
#and now we can run some queries against our table
>>> ExampleModel.objects.count()
8
>>> q = ExampleModel.objects(example_type=1)
>>> q.count()
4
>>> for instance in q:
>>> print instance.description
example5
example6
example7
example8
#here we are applying additional filtering to an existing query
#query objects are immutable, so calling filter returns a new
#query object
>>> q2 = q.filter(example_id=em5.example_id)
>>> q2.count()
1
>>> for instance in q2:
>>> print instance.description
example5If you'd like to contribute to cqlengine, please read the contributor guidelines
cqlengine was developed primarily by (Blake Eggleston)blakeeggleston and Jon Haddad, with contributions from several others in the community.