Cassandra 3.1 python driver 'no viable alternative at input describe'

Question

I can't run describe keyspaces for some reason, even though I'm clearly connecting to my Cassandra 3.3 host via the 3.1 python driver. Some other commands seem to work fine.

Thanks in advance!

    from cassandra.cluster import Cluster
        cluster = Cluster(['192.168.1.53'])
        #session = cluster.connect('node_data')
        session = cluster.connect()
        session.execute('USE node_data')
        rows = session.execute('SELECT * FROM users')
        session.execute('DESCRIBE KEYSPACES;')

---------------------------------------------------------------------------
SyntaxException                           Traceback (most recent call last)
<ipython-input-5-8b1f82917aa9> in <module>()
----> 1 session.execute('DESCRIBE KEYSPACES;')
      2 

/Users/natemarks/.virtualenvs/cassandra/lib/python2.7/site-packages/cassandra/cluster.so in cassandra.cluster.Session.execute (cassandra/cluster.c:27107)()

/Users/natemarks/.virtualenvs/cassandra/lib/python2.7/site-packages/cassandra/cluster.so in cassandra.cluster.ResponseFuture.result (cassandra/cluster.c:60227)()

SyntaxException: <ErrorMessage code=2000 [Syntax error in CQL query] message="line 1:0 no viable alternative at input 'DESCRIBE' ([DESCRIBE]...)">

Answer 1

DESCRIBE is a cqlsh-specific command, so it is not supported by the drivers since it is not considered a CQL command. You can find a full listing of the cqlsh commands here.

Alternatively you can get at a keyspace's schema using the python-driver by accessing Cluster.metadata and then accessing the keyspaces dict.

Answer 2

cluster.metadata.keyspaces
cluster.metadata.keyspaces['node_data']
cluster.metadata.keyspaces['node_data'].tables
cluster.metadata.keyspaces['node_data'].tables['users']
cluster.metadata.keyspaces['node_data'].tables['users'].columns
cluster.metadata.keyspaces['node_data'].tables['users'].columns['uid']

By accessing the cluster metadata you can get all info related to any keyspace, table, and column stored in the given cassandra cluster.