cqlengine is a Cassandra CQL 3 Object Mapper for Python
Users of versions < 0.4, please read this post: 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)...
>>> from cqlengine import connection
>>> connection.setup(['127.0.0.1:9160'])
#...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