benoitc/couchdbkit

About

Couchdbkit provides you a full featured and easy client to access and manage CouchDB. It allows you to manage a CouchDBserver, databases, doc managements and view access. All objects mostly reflect python objects for convenience. Server and Databases objects could be used for example as easy as using a dict.

Installation

Couchdbkit requires Python 2.x superior to 2.6.

To install couchdbkit using pip you must make sure you have a recent version of distribute installed:

$ curl -O http://python-distribute.org/distribute_setup.py
$ sudo python distribute_setup.py
$ easy_install pip

To install or upgrade to the latest released version of couchdbkit:

$ pip install couchdbkit

Getting started

This tutorial exposes key features of this library mainly through code examples. For in-depth description of the modules, you'll want to read the API documentation.

Write your first CouchDB document

from couchdbkit import Server
# server object
server = Server()

# create database
db = server.get_or_create_db("greeting")

doc = {"mydoc": "test"}
db.save_doc(doc)

import datetime
from couchdbkit import *

class Greeting(Document):
    author = StringProperty()
    content = StringProperty()
    date = DateTimeProperty()

Store the submitted Greetings

Here is the code to save a greet on Greeting database. We also see how to create a database:

from couchdbkit import Server

# associate Greeting to the db
Greeting.set_db(db)

# create a new greet
greet = Greeting(
    author="Benoit",
    content="Welcome to couchdbkit world",
    date=datetime.datetime.utcnow()
)

# save it
greet.save()

Your document greet is now in the greetings db. Each document is saved with a doc_type field that allow you to find easily each kind of document with the views. By default doc_type is the name of the class.

Now that you saved your document, you can update it:

greet.author = u"Benoit Chesneau"
greet.save()

Here we updated the author name.

Dynamic properties

Mmm ok, but isn't CouchDB storing documents schema less? Do you want to add a property ? Easy:

greet.homepage = "http://www.e-engura.org"
greet.save()

Now you have just added an homepage property to the document.

Get all greetings

You first have to create a view and save it in the db. We will call it greeting/all. To do this we will use the loader system of couchdbkit that allows you to send views to CouchDB.

Let's create a folder that contains the design doc, and then the folder for the view. On unix:

mkdir -p ~/Work/couchdbkit/example/_design/greeting/views/all

In this folder we edit a file map.js:

function(doc) {
  if (doc.doc_type == "Greeting")
    emit(doc._id, doc);
    }
}

Here is a folder structure:

/Work/couchdbkit/example/:

--_design/
---- greetings
------ view

Here is a screenshot:

A system will be provided to manage view creation and other things. As some noticed, this system works like couchapp and is fully compatible.

Then we use push function to send the design document to CouchDB:

from couchdbkit.designer import push
push('/path/to/example/_design/greetings', db)

The design doc is now in the greetings database and you can get all greets:

greets = Greeting.view('greeting/all')