Python couchbase lite c

Python bindings for couchbase lite c.

Documentation

github	https://github.com/couchbaselabs/couchbase-lite-C
swift docs	https://docs.couchbase.com/couchbase-lite/current/swift/learn/swift-database.html
N1QL docs	https://www.couchbase.com/products/n1ql

Install

1. Build/Install couchbase lite c.

2. Build/Install bindings

# from repo root
cd bindings/python
pip install cffi
./build.sh
test/test.sh

# install to desired environment
# cp -Ra CouchbaseLite /usr/lib/python3.9/site-packages/

Usage

The python bindings are modeled after the official swift API.

Database

A database is a container for documents

from CouchbaseLite import Database as database

# normal
config = database.DatabaseConfiguration('/var/tmp')
db = database.Database('db_filename', config)
# /var/tmp/db_filename.cblite2/

# with encryption
# TODO!

Documents

Documents are stored as JSON objects.

There are 2x Document Types:

• Document
• MutableDocument

Do not use key names that start with an underscore - those are reserved.

from CouchbaseLite import Document as document

with db:
    doc = document.MutableDocument('foo')          # id=='foo'
    doc.properties.update({'red': 1})
    db.getDocument('foo').properties               # {'red': 1}
    db.saveDocument(doc)

    mdoc = document.MutableDocument('foo')          # id=='foo'
    mdoc.properties.update({'blue': 1})
    mdoc['blue']                                   # 1
    db.getDocument('foo').properties               # {'blue': 1}
    db.saveMutableDocument(mdoc)

Blobs

Blobs are binary blobs. They can be assigned as values on documents.

NOTE:

I believe blob data is automatically serialized/deserialized when document is saved/retrieved. Untested.

from CouchbaseLite import Blob as blob

with open('out.png') as fd:
    png_contents = fd.read()

b = blob.Blob(png_contents, contentType='image/png')

Query

JSONQuery

TODO:

find spec for JSON query syntax

from CouchbaseLite import Query as query

q = query.JSONQuery(db, {...})
print(q.explanation)

for row in q.execute():
    print(row.asArray())
    print(row.asDictionary())

N1QL

SQL-like queries that operate on json objects. See N1QL for syntax.

from CouchbaseLite import Query as query

q = query.N1QLQuery(db, 'SELECT * FROM bucket')
q.execute():

Live Query

Use Listeners to monitor database for changes to particular documents.
Queries remain perpetually active, behave as a subscription.

def my_listener(doc_ids):
    print('ids changed: {}'.format(doc_ids))

listener = db.addListener(my_listener)

# ... work with db

listener.remove()

Replication

Replication is handled using a different the sync_gateway tool.
See couchbase for details.