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https://github.com/pycassa/pycassa

Python Thrift driver for Apache Cassandra
https://github.com/pycassa/pycassa

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Python Thrift driver for Apache Cassandra

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pycassa

=======



[![Build Status](https://secure.travis-ci.org/pycassa/pycassa.png?branch=master)](http://travis-ci.org/pycassa/pycassa)



pycassa is a Thrift-based python client library for [Apache Cassandra](http://cassandra.apache.org)



**pycassa does not support CQL** or Cassandra's native protocol, which are a

replacement for the Thrift interface that pycassa is based on. If you are

starting a new project, **it is highly recommended that you use the newer**

[DataStax python driver](https://github.com/datastax/python-driver) instead

of pycassa.



pycassa is open source under the [MIT license](http://www.opensource.org/licenses/mit-license.php).



Documentation

-------------



Documentation can be found here:



[http://pycassa.github.com/pycassa/](http://pycassa.github.com/pycassa/)



It includes [installation instructions](http://pycassa.github.com/pycassa/installation.html),

a [tutorial](http://pycassa.github.com/pycassa/tutorial.html),

[API documentation](http://pycassa.github.com/pycassa/api/index.html),

and a [change log](http://pycassa.github.com/pycassa/changelog.html).



Getting Help

------------



IRC:



* Use the #cassandra channel on irc.freenode.net. If you don't have an IRC client,

  you can use [freenode's web based client](http://webchat.freenode.net/?channels=#cassandra).



Mailing List:



* User list: [http://groups.google.com/group/pycassa-discuss](http://groups.google.com/group/pycassa-discuss)

* Developer list: [http://groups.google.com/group/pycassa-devel](http://groups.google.com/group/pycassa-devel)



Installation

------------



If pip is available, you can install the lastest pycassa release

with:



    pip install pycassa



If you want to install from a source checkout, make sure you have Thrift

installed, and run setup.py as a superuser:



    pip install thrift

    python setup.py install



Basic Usage

-----------



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



~~~~~~ {python}

>>> 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=['192.168.2.10'])

~~~~~~



To use the standard interface, create a ColumnFamily instance.



~~~~~~ {python}

>>> 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:



~~~~~~ {python}

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

>>> cf.get('foo')

{'column1': 'val2'}

~~~~~~



You may insert multiple columns at once:



~~~~~~ {python}

>>> cf.insert('bar', {'column1': 'val3', 'column2': 'val4'})

>>> cf.multiget(['foo', 'bar'])

{'foo': {'column1': 'val2'}, 'bar': {'column1': 'val3', 'column2': 'val4'}}

>>> cf.get_count('bar')

2

~~~~~~



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



~~~~~~ {python}

>>> 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:



~~~~~~ {python}

>>> cf.remove('bar', columns=['column1'])

>>> cf.get('bar')

{'column2': 'val4'}

>>> cf.remove('bar')

>>> cf.get('bar')

Traceback (most recent call last):

...

pycassa.NotFoundException: NotFoundException()

~~~~~~



See the [tutorial](http://pycassa.github.com/pycassa/tutorial.html#connecting-to-cassandra) for more details.