kev

K.E.V. (Keys, Extra Stuff, and Values) is a Python ORM for key-value stores and document databases based on Valley. Currently supported backends are Redis, S3 and a S3/Redis hybrid backend.

Python Versions

Kev should work on Python 3.5+ and higher

Install

pip install kev

Example Project Using KEV

• flask-capless-blog

Example Usage

Setup the Connection

Example: loading.py

fromkev.loadingimportKevHandlerkev_handler=KevHandler({
's3':{
'backend':'kev.backends.s3.db.S3DB',
'connection':{
'bucket':'your-bucket-name'
}
},
's3redis':{
'backend':'kev.backends.s3redis.db.S3RedisDB',
'connection':{
'bucket':'your-bucket-name',
'indexer':{
'host':'your.redis.host.com',
'port':6379,
}
}
},
'redis': {
'backend': 'kev.backends.redis.db.RedisDB',
'connection': {
'host': 'your-redis-host.com',
'port': 6379,
}
},
})

Setup the Models

Example: models.py

fromkevimport (Document,CharProperty,DateTimeProperty,
DateProperty,BooleanProperty,IntegerProperty,
FloatProperty)
from .loadingimportkev_handlerclassTestDocument(Document):
name=CharProperty(required=True,unique=True,min_length=3,max_length=20)
last_updated=DateTimeProperty(auto_now=True)
date_created=DateProperty(auto_now_add=True)
is_active=BooleanProperty(default_value=True,index=True)
city=CharProperty(required=False,max_length=50)
state=CharProperty(required=True,index=True,max_length=50)
no_subscriptions=IntegerProperty(default_value=1,index=True,min_value=1,max_value=20)
gpa=FloatProperty()
def__unicode__(self):
returnself.nameclassMeta:
use_db='s3redis'handler=kev_handler

Use the model

How to Save a Document

>>>from .modelsimportTestDocument>>>kevin=TestDocument(name='Kev',is_active=True,no_subscriptions=3,state='NC',gpa=3.25)
>>>kevin.save()
>>>kevin.name'Kev'>>>kevin.is_activeTrue>>>kevin.pkec640abfd6>>>kevin.idec640abfd6>>>kevin._id'ec640abfd6:id:s3redis:testdocument'

Query Documents

First Save Some More Docs

>>>george=TestDocument(name='George',is_active=True,no_subscriptions=3,gpa=3.25,state='VA')
>>>george.save()
>>>sally=TestDocument(name='Sally',is_active=False,no_subscriptions=6,gpa=3.0,state='VA')
>>>sally.save()

Show all Documents

>>>TestDocument.objects().all()
[<TestDocument: Kev:ec640abfd6>,<TestDocument: George:aff7bcfb56>,<TestDocument: Sally:c38a77cfe4>]
>>>TestDocument.objects().all(skip=1)
[<TestDocument: George:aff7bcfb56>,<TestDocument: Sally:c38a77cfe4>]
>>>TestDocument.objects().all(limit=2)
[<TestDocument: Kev:ec640abfd6>,<TestDocument: George:aff7bcfb56>]

Get One Document

>>>TestDocument.get('ec640abfd6')
<TestDocument: Kev:ec640abfd6>>>>TestDocument.objects().get({'state':'NC'})
<TestDocument: Kev:ec640abfd6>

Filter Documents

>>>TestDocument.objects().filter({'state':'VA'})
[<TestDocument: George:aff7bcfb56>,<TestDocument: Sally:c38a77cfe4>]
>>>TestDocument.objects().filter({'no_subscriptions':3})
[<TestDocument: Kev:ec640abfd6>,<TestDocument: George:aff7bcfb56>]
>>>TestDocument.objects().filter({'no_subscriptions':3,'state':'NC'})
[<TestDocument: Kev:ec640abfd6>]

Sort Documents

>>>TestDocument.objects().filter({'no_subscriptions':3}).sort_by('name')
[<TestDocument: George:aff7bcfb56>, <TestDocument: Kev:ec640abfd6>]
>>>TestDocument.objects().filter({'no_subscriptions':3}).sort_by('name', reverse=True)
[<TestDocument: Kev:ec640abfd6>, <TestDocument: George:aff7bcfb56>]
>>>TestDocument.objects().all().sort_by('gpa')
[<TestDocument: Sally:c38a77cfe4>, <TestDocument: Kev:ec640abfd6>, <TestDocument: George:aff7bcfb56>]
TestDocument.objects().all().sort_by('name').sort_by('gpa')
[<TestDocument: Sally:c38a77cfe4>, <TestDocument: George:aff7bcfb56>>, <TestDocument: Kev:ec640abfd6]

Chain Filters

The chain filters feature is only available for Redis and S3/Redis backends.

>>>TestDocument.objects().filter({'no_subscriptions':3}).filter({'state':'NC'})
[<TestDocument: Kev:ec640abfd6>]

Wildcard Filters

Wildcard filters currently only work with the Redis and S3/Redis backend. Use prefixes with the S3 backend.

>>>TestDocument.objects().filter({'state':'N*'})
[<TestDocument: Kev:ec640abfd6>]

Prefix Filters

Prefix filters currently only work with the S3 backend. Use wildcard filters with the Redis or S3/Redis backends.

>>>TestDocument.objects().filter({'state':'N'})
[<TestDocument: Kev:ec640abfd6>]

Backup and Restore

Easily backup or restore your model locally or from S3. The backup method creates a JSON file backup.

Backup

Local Backup

TestDocument().backup('test-backup.json')

S3 Backup

TestDocument().backup('s3://your-bucket/kev/test-backup.json')

Restore

Local Restore

TestDocument().restore('test-backup.json')

S3 Restore

TestDocument().restore('s3://your-bucket/kev/test-backup.json')

Author

Twitter::@brianjinwrightGithub:bjinwright