This document discusses using NoSQL databases with Python. It introduces Cassandra and its data model, and demonstrates how to install and use Cassandra from the command line and with the Python driver Pycassa. It shows how to perform basic operations like inserting, retrieving, and deleting data using both low-level Thrift APIs and higher-level Pycassa APIs.

2. NoSQL com Python
Gustavo Pinto
@gustavopinto

3. gustavopinto
2004 - belém, grad, php
2006 - amazontic, java, rails
2008 - curitiba, msc, python
2009 - aprioriti, xp, scrum
2011 - recife, phd

4. novo século
novos problemas

9. O que você usaria?

10. O que você usaria?

17. NoSQL

18. Hash table
+
Distributed

20. Vamos por
partes..

21. Estrutura de
dados

22. Desnormalização
JOIN

24. eventualmente
consistente
Replication Factor = 3

25. tolerante
a
falhas

26. BASE ACID
● Basically ● Atomic
● Available ● Consistent
● Soft State ● Isolated
● Eventually ● Durable
Consistent

27. ferramentas

30. Banco de dados distribuido,
tolerante a falhas, escalável,
orientado a colunas

31. x
... em 50 GB de dados

32. Intalação
● download cassanda-xxx.tar.gz
● cd cassandra/bin/
● ./cassandra

33. Intalação
● download cassanda-xxx.tar.gz
● cd cassandra/bin/
● ./cassandra

34. Intalação
● download cassanda-xxx.tar.gz
● cd cassandra/bin/
● ./cassandra
● ./cassandra-cli -h localhost -p 9160

35. show keyspaces;

36. create keyspace pugpe;
use pugpe;

37. create column family encontroxvi with comparator = UTF8Type;

38. set encontroxvi['08:30~09:00']['Titulo'] = 'Apresentacao';
set encontroxvi['08:30~09:00']['Palestrante'] = 'Marcel';

39. set encontroxvi['08:30~09:00']['Titulo'] = 'Apresentacao';
set encontroxvi['08:30~09:00']['Palestrante'] = 'Marcel';

40. set encontroxvi['08:30~09:00']['Titulo'] = 'Apresentacao';
set encontroxvi['08:30~09:00']['Palestrante'] = 'Marcel';

41. set encontroxvi['08:30~09:00']['Titulo'] = 'Apresentacao';
set encontroxvi['08:30~09:00']['Palestrante'] = 'Marcel';

42. set encontroxvi['08:30~09:00']['Titulo'] = 'Apresentacao';
set encontroxvi['08:30~09:00']['Palestrante'] = 'Marcel';
set encontroxvi['09:00~09:40']['Titulo'] = 'noSQL';
set encontroxvi['09:00~09:40']['Palestrante'] = 'Gustavo';
set encontroxvi['09:00~09:40']['Slide'] = 'bit.ly/jhae1';

43. get encontroxvi['08:30~09:00'];

44. get encontroxvi['08:30~09:00'];

45. Thrift
Idiomatic low level API

46. Instalação
1. Download thrift-0.2.0-incubating.tar.gz
2. Instale as dependências (apt-get install ..)
3. ./configure (se tudo der certo)
4. make (se tudo der certo..)
5. make install

47. Instalação
1. Download thrift-0.2.0-incubating.tar.gz
2. Instale as dependências (apt-get install ..)
3. ./configure (se tudo der certo)
4. make (se tudo der certo..)
5. make install

48. from thrift import Thrift
from thrift.transport import TTransport
from thrift.transport import TSocket
from thrift.transport import THttpClient
from thrift.protocol import TBinaryProtocol
from cassandra import Cassandra
from cassandra.ttypes import *
import time
socket = TSocket.TSocket("localhost", 9160)
transport = TTransport.TBufferedTransport(socket)
protocol = TBinaryProtocol.TBinaryProtocol(transport)
client = Cassandra.Client(protocol)

49. keyspace = "pugpe"
column_path = ColumnPath(column_family="encontroxvi",
column="palestrante")
key = "08:30~09:00"
value = "Gustavo Pinto"
timestamp = time.time()
try:
transport.open()
# ...
client.insert(keyspace,key, column_path, value,
timestamp,ConsistencyLevel.ZERO)
# ....

50. column_parent = ColumnParent(column_family="
encontroxvi")
slice_range = SliceRange(start="", finish="")
predicate = SlicePredicate(slice_range=slice_range)
result = client.get_slice(keyspace, key,
column_parent, predicate, ConsistencyLevel.ONE)
# ...

51. pycassa
High level API

52. Instalação
1. easy_install pycassa

53. import pycassa
pool = pycassa.ConnectionPool("pugpe")
cf = pycassa.ColumnFamily(pool, "encontroxvi")
cf.insert('08:30~09:00', {'palestrante' : 'marcel', 'palestra' :
'abertura'})
cf.insert('09:00~09:40', {'palestrante' : 'gustavopinto', 'palestra'
: 'nosql', 'slide' : 'bit.ly/...'})
cf.get('08:30~09:00')
cf.multiget(['08:30~09:00', '09:00~09:40'])
cf.get_count('09:00~09:40')
cf.remove('09:00~09:40')

54. import pycassa
pool = pycassa.ConnectionPool("pugpe")
cf = pycassa.ColumnFamily(pool, "encontroxvi")
cf.insert('08:30~09:00', {'palestrante' : 'marcel', 'palestra' :
'abertura'})
cf.insert('09:00~09:40', {'palestrante' : 'gustavopinto', 'palestra'
: 'nosql', 'slide' : 'bit.ly/...'})
cf.get('08:30~09:00')
cf.multiget(['08:30~09:00', '09:00~09:40'])
cf.get_count('09:00~09:40')
cf.remove('09:00~09:40')

55. import pycassa
pool = pycassa.ConnectionPool("pugpe")
cf = pycassa.ColumnFamily(pool, "encontroxvi")
cf.insert('08:30~09:00', {'palestrante' : 'marcel', 'palestra' :
'abertura'})
cf.insert('09:00~09:40', {'palestrante' : 'gustavopinto', 'palestra'
: 'nosql', 'slide' : 'bit.ly/...'})
cf.get('08:30~09:00')
cf.multiget(['08:30~09:00', '09:00~09:40'])
cf.get_count('09:00~09:40')
cf.remove('09:00~09:40')

56. import pycassa
pool = pycassa.ConnectionPool("pugpe")
cf = pycassa.ColumnFamily(pool, "encontroxvi")
cf.insert('08:30~09:00', {'palestrante' : 'marcel', 'palestra' :
'abertura'})
cf.insert('09:00~09:40', {'palestrante' : 'gustavopinto',
'palestra' : 'nosql', 'slide' : 'bit.ly/...'})
cf.get('08:30~09:00')
cf.multiget(['08:30~09:00', '09:00~09:40'])
cf.get_count('09:00~09:40')
cf.remove('09:00~09:40')

57. import pycassa
pool = pycassa.ConnectionPool("pugpe")
cf = pycassa.ColumnFamily(pool, "encontroxvi")
cf.insert('08:30~09:00', {'palestrante' : 'marcel', 'palestra' :
'abertura'})
cf.insert('09:00~09:40', {'palestrante' : 'gustavopinto', 'palestra'
: 'nosql', 'slide' : 'bit.ly/...'})
cf.get('08:30~09:00')
cf.multiget(['08:30~09:00', '09:00~09:40'])
cf.get_count('09:00~09:40')
cf.remove('09:00~09:40')

58. import pycassa
pool = pycassa.ConnectionPool("pugpe")
cf = pycassa.ColumnFamily(pool, "encontroxvi")
cf.insert('08:30~09:00', {'palestrante' : 'marcel', 'palestra' :
'abertura'})
cf.insert('09:00~09:40', {'palestrante' : 'gustavopinto', 'palestra'
: 'nosql', 'slide' : 'bit.ly/...'})
cf.get('08:30~09:00')
cf.multiget(['08:30~09:00', '09:00~09:40'])
cf.get_count('09:00~09:40')
cf.remove('09:00~09:40')

61. Para saber mais
https://bitly.com/bundles/gustavopinto/2

62. Para saber mais