PyCouchbase

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Why add another layer to the SDK?

Inconsistent data types in Couchbase documents can be a real pain.
Better management of multiple Couchbase connections.
Readability of Couchbase documents in the Python source code while still being able to use Couchbase SDK's operations.

Features

This was originally forked from and inspired by couchbasekit.
Validate Couchbase documents.
Represent Couchbase documents as Python objects.
Easily manage multiple Couchbase connections.
Supports Couchbase Python SDK 2.0 operations.
There are data retrieval operations that are already included in couchbasekit but I haven't thoroughly tested it with PyCouchbase.

Dependencies

This package uses libffi:

On Ubuntu/Debian machines, run:

$ sudo apt-get -y install libffi-dev

On CentOS/Redhat machines, run:

$ sudo yum install -y libffi libffi-devel

Installation

At the command line:

$ easy_install pycouchbase

Or, if you have virtualenvwrapper installed:

$ mkvirtualenv pycouchbase
$ pip install pycouchbase

Getting Started

Let us go through a simple example.

Import everything we need:

import datetime

from pycouchbase import Connection
from pycouchbase import Document, register_view
from pycouchbase.fields import EmailField, ChoiceField

Declare the Document class:

# You can define your own field/data type

class Gender(ChoiceField):
    CHOICES = {
        'M': 'Male',
        'F': 'Female',
    }

@register_view('dev_authors')
class Author(Document):
    __bucket_name__ = 'couchbasekit_samples'
    __key_field__ = 'slug'  # optional
    doc_type = 'author'
    structure = {
        'slug': unicode,
        'first_name': unicode,
        'last_name': unicode,
        'gender': Gender,
        'email': EmailField,
        'has_book': bool,
        'age': int,
        'birthday': datetime.date,
        'created_at': datetime.datetime,
    }
    default_values = {  # optional
        'has_book': False,
        # don't worry about the timezone info!
        # it's auto assigned as to UTC, so all you have to do is:
        'created_at': datetime.datetime.utcnow,
    }
    required_fields = (  # optional
        'slug',
        'first_name',
        'last_name',
        'email',
    )

Validate and save your document:

local_connection = Connection.auth(server='localhost')
author = Author()
bucket = author.get_bucket(local_connection)

author.update({
    'slug': u'douglas_adams',
    'first_name': u'Douglas',
    'last_name': u'Adams',
    'gender': Gender('M'),
    'email': EmailField('dna@example.com'),
})

# Try to validate before saving
try:
    author.validate()
    try:
        rvs = bucket.insert(author.slug, author.encode())
    except KeyExistsError as why:
        print(why)
except Author.StructureError as why:
    # when the data structure is invalid
    print(why)

Save multiple documents:

local_connection = Connection.auth(server='localhost')
author = Author()

list_data = [{
    'slug': u'douglas_adams',
    'first_name': u'Douglas',
    'last_name': u'Adams',
    'gender': Gender('M'),
    'email': EmailField('dna@example.com'),
}, {
    'slug': u'isaac_asimov',
    'first_name': u'Isaac',
    'last_name': u'Asimov',
    'gender': Gender('M'),
    'email': EmailField('dna@example.com'),
}]

try:
    bucket = author.get_bucket(local_connection)
    updated_authors = {}

    for d in list_data:
        author.update(d)
        try:
            # validate!
            author.validate()
            updated_authors.update({
                d['slug']: author.encode()
            })
        except author.StructureError as why:
            print(why)

    # save multiple data
    rvs = bucket.upsert_multi(updated_authors)
except CouchbaseNetworkError as why:
    print(why)

Manage multiple connections:

connection_1 = Connection.auth(server='server_1')
connection_2 = Connection.auth(server='server_2')

# where doc_1 and doc_2 are document objects
bucket_1 = doc_1.get_bucket(connection_1)
bucket_2 = doc_2.get_bucket(connection_2)

Bucket objects can support any Couchbase Python SDK 2.0 operations:

bucket_1.get('key_or_id')
bucket_1.insert('key_or_id', value)

More about Couchbase SDK's supported operations here: http://docs.couchbase.com/developer/python-2.0/introduction.html

Contributing

Contributions/feedback are welcome and greatly appreciated! More about it here: https://github.com/ardydedase/pycouchbase/blob/master/CONTRIBUTING.rst

TODOs

More unit tests
Better error handling

ardydedase / pycouchbase