Skip to content


Subversion checkout URL

You can clone with
Download ZIP
Fetching contributors…
Cannot retrieve contributors at this time
121 lines (88 sloc) 3.36 KB


pycassa is a python client library for Apache Cassandra with the following features:

  • Automatic failover and operation retries
  • Connection pooling
  • Multithreading support
  • A batch interface
  • A class for mapping classes to Cassandra column families

The latest release is fully compatible with Cassandra 0.8 and 1.0, and compatible with data API of 0.7.

pycassa is open source under the MIT license.


Documentation can be found here:

It includes installation instructions, a tutorial, API documentation, and a change log.

Getting Help


Mailing List:


If easy_install is available, you can install the lastest pycassa release with:

easy_install pycassa

If you want to install from a source checkout, make sure you have Thrift installed, and run as a superuser:

easy_install thrift
python install

Basic Usage

To get a connection pool, pass a Keyspace and an optional list of servers:

>>> import pycassa
>>> pool = pycassa.ConnectionPool('Keyspace1') # Defaults to connecting to the server at 'localhost:9160'
>>> # or, we can specify our servers:
>>> pool = pycassa.ConnectionPool('Keyspace1', server_list=[''])

To use the standard interface, create a ColumnFamily instance.

>>> pool = pycassa.ConnectionPool('Keyspace1')
>>> cf = pycassa.ColumnFamily(pool, 'Standard1')
>>> cf.insert('foo', {'column1': 'val1'})
>>> cf.get('foo')
{'column1': 'val1'}

insert() will also update existing columns:

>>> cf.insert('foo', {'column1': 'val2'})
>>> cf.get('foo')
{'column1': 'val2'}

You may insert multiple columns at once:

>>> cf.insert('bar', {'column1': 'val3', 'column2': 'val4'})
>>> cf.multiget(['foo', 'bar'])
{'foo': {'column1': 'val2'}, 'bar': {'column1': 'val3', 'column2': 'val4'}}
>>> cf.get_count('bar')

get_range() returns an iterable. You can use list() to convert it to a list:

>>> list(cf.get_range())
[('bar', {'column1': 'val3', 'column2': 'val4'}), ('foo', {'column1': 'val2'})]
>>> list(cf.get_range(row_count=1))
[('bar', {'column1': 'val3', 'column2': 'val4'})]

You can remove entire keys or just a certain column:

>>> cf.remove('bar', columns=['column1'])
>>> cf.get('bar')
{'column2': 'val4'}
>>> cf.remove('bar')
>>> cf.get('bar')
Traceback (most recent call last):
cassandra.ttypes.NotFoundException: NotFoundException()

See the tutorial for more details.

Jump to Line
Something went wrong with that request. Please try again.