redisco 0.1.dev6

Python Containers and Simple Models for Redis

Python Containers and Simple Models for Redis

Description

Redisco allows you to store objects in Redis. It is inspired by Ruby library Ohm and its design and code are loosely based on Ohm and the Django ORM. It is built on top of redis-py. It includes container classes that allow easier access to Redis sets, lists, and sorted sets.

Installation

Redisco requires latest version of redis-py so get it first.

pip install git+http://github.com/andymccurdy/redis-py.git@master#egg=redis-py

Then install redisco.

pip install git+http://github.com/iamteem/redisco.git@master#egg=redisco

Models

Example

from redisco import models
class Person(models.Model):::
    name = models.Attribute(required=True)
    created_at = models.DateTimeField(auto_add=True)
    fave_colors = models.ListField(str)

>>> person = Person(name="Conchita")
>>> person.is_valid()
True
>>> person.save()
True
>>> conchita = Person.objects.filter(name='Conchita')[0]
>>> conchita.name
'Conchita'
>>> conchita.created_at
datetime.datetime(2010, 5, 24, 16, 0, 31, 954704)

Model Attributes

Here are the model attributes and value types they can store.

Attribute:

unicode

IntegerField:

int

DateTimeField:

DateTime

DateField:

Date

FloatField:

float

BooleanField:

bool

ReferenceField:

reference to another model

ListField:

list of unicode, int, float, models

Options for creating attributes include required, default, and validator. DateField and DateTimeField have the auto_now_add and auto_now.

Queries

Queries are executed using a manager, accessed via the objects class attribute.

Examples

Person.objects.all()
Person.objects.filter(name='Conchita')
Person.objects.filter(name='Conchita').first()
Person.objects.all().order('name')
Person.objects.filter(fave_colors='Red')

Ranged Queries

Redisco has a limited support for queries involving ranges – it can only filter fields that are numeric, i.e. DateField, DateTimeField, IntegerField, and FloatField. The zfilter method of the manager is used for these queries.

Person.objects.zfilter(created_at__lt=datetime(2010, 4, 20, 5, 2, 0))
Person.objects.zfilter(created_at__gte=datetime(2010, 4, 20, 5, 2, 0))
Person.objects.zfilter(created_at__in=(datetime(2010, 4, 20, 5, 2, 0), datetime(2010, 5, 1)))

Containers

Redisco has three containers that roughly match Redis’s supported data structures: lists, sets, sorted set. Anything done to the container is persisted to Redis.

Sets

>>> import redis
>>> from redisco.containers import Set
>>> s = Set('myset')
>>> s.add('apple')
>>> s.add('orange')
>>> s.members
set(['orange', 'apple'])
>>> t = Set('nset')
>>> t.add('kiwi')
>>> t.add('guava')
>>> t.members
set(['kiwi', 'guava'])
>>> s.update(t)
>>> s.members
set(['kiwi', 'orange', 'guava', 'apple'])

Lists

>>> import redis
>>> from redisco.containers import List
>>> l = List('alpha')
>>> l.append('a')
>>> l.append('b')
>>> l.append('c')
>>> 'a' in l
True
>>> 'd' in l
False
>>> len(l)
3
>>> l.index('b')
1
>>> l.members
['a', 'b', 'c']

Sorted Sets

>>> zset = SortedSet('zset')
>>> zset.members
['d', 'a', 'b', 'c']
>>> 'e' in zset
False
>>> 'a' in zset
True
>>> zset.rank('d')
0
>>> zset.rank('b')
2
>>> zset[1]
'a'
>>> zset.add('f', 200)
>>> zset.members
['d', 'a', 'b', 'c', 'f']
>>> zset.add('d', 99)
>>> zset.members
['a', 'b', 'c', 'd', 'f']