Python Driver 3.7.0 Released

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from cassandra.cluster import Cluster, ExecutionProfile

from cassandra.policies import ConstantSpeculativeExecutionPolicy

from cassandra.query import SimpleStatement

cluster = Cluster()

# send a new request every 100ms for a maximum of 10 attempts

ep = ExecutionProfile(speculative_execution_policy=ConstantSpeculativeExecutionPolicy(.1, 10))

cluster.add_execution_profile('my_app_ep', ep)

session = cluster.connect('test')

statement = SimpleStatement("SELECT i FROM d WHERE k = 0", is_idempotent=True)

result = session.execute(statement, execution_profile='my_app_ep')

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query = "SELECT * FROM users"

statement = SimpleStatement(query, fetch_size=10)

results = session.execute(statement)

# save the paging_state somewhere...

session['paging_state'] = results.paging_state

# and use it later to resume the pagination

query = "SELECT * FROM users"

statement = SimpleStatement(query, fetch_size=10)

paging_state = session['paging_state']

results = session.execute(statement, paging_state=paging_state)

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from cassandra.cluster import Cluster

from cassandra.policies import EC2MultiRegionTranslator

cluster = Cluster(['127.0.0.1'], address_translator=EC2MultiRegionTranslator())

session = cluster.connect()

# do stuff...

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from cassandra.cqlengine import connection

# ...

CONNS = ['cluster1', 'cluster2']

KEYSPACES = ('client1', 'client2', 'client3', 'client4')

connection.register_connection('cluster1', ['127.0.0.1'], default=True)

connection.register_connection('cluster2', ['127.0.0.50'], lazy_connect=True)

for keyspace in KEYSPACES:

    keyspace_simple(keyspace, 3, connections=CONNS)

class Automobile(Model):

    __connection__ = 'cluster2'  # default connection per model

    manufacturer = columns.Text(primary_key=True)

    year = columns.Integer(primary_key=True)

    model = columns.Text()

# sync the table for all connections and keyspaces

sync_table(Automobile, KEYSPACES, CONNS)

# Select the connection and keyspace via the ContextQuery

with ContextQuery(Automobile, connection='cluster1' keyspace='client2') as A:

    A.objects.create(manufacturer='honda', year=2004, model='civic')

# Read from the default model connection 'cluster2'

print len(Automobile.objects.using(keyspace='client2').get(manufacturer='honda', year=2004))  # 0

# Select the connection and keyspace on the fly

print len(Automobile.objects.using(connection='cluster1', keyspace='client2').all())  # 1

# Select on the model instance

a = Automobile.objects.using(connection='cluster1',keyspace='client2').get(manufacturer='honda', year=2004)

a.using('cluster2').save()  # save on cluster2 rather than cluster1

# Connection select with a BatchQuery

with BatchQuery(connection='cluster1' keyspace='client4') as b:

    A.objects.batch(b).create(manufacturer='honda', year=2004, model='civic')

    A.objects.batch(b).create(manufacturer='honda', year=2005, model='civic')

    A.objects.batch(b).create(manufacturer='honda', year=2006, model='civic')