CouchDB3

CouchDB3

CouchDB3 is a wrapper around the CouchDB API. For more detailed information, please refer to the documentation.

Disclaimer

Big parts of the documentation (and thus docstrings) have been copied from CouchDB's API's great official documentation.

Requirements

• Python version >= 3.7
• CouchDB version 3.x

Installation

Installing via PyPi

pip install couchdb3

Installing via Github

python -m pip install git+https://github.com/n-Vlahovic/couchdb3.git

Installing from source

git clone https://github.com/n-Vlahovic/couchdb3
python -m pip install -e couchdb3

Quickstart

Connecting to a database server

import couchdb3

client = couchdb3.Server(
    "http://user:password@127.0.0.1:5984"
)

# Checking if the server is up
print(client.up())
# True

user and password can also be passed into the Server constructor as keyword parameters, e.g.

client = couchdb3.Server(
    "127.0.0.1:5984",  # Scheme omitted - will assume http protocol
    user="user",
    password="password"
)

Both approaches are equivalent, i.e. in both cases the instance's scheme,host,port,user,password will be identical.

Further, clients can be used with context managers:

with couchdb3.Server("http://user:password@127.0.0.1:5984") as client:
    # Do stuff
    ...

Getting or creating a database

dbname = "mydb"
db = client.get(dbname) if dbname in client else client.create(dbname)
print(db)
# Database: mydb

Creating a document

mydoc = {
    "_id": "mydoc-id",
    "name": "Hello",
    "type": "World"
}
print(db.save(mydoc))
# ('mydoc-id', True, '1-24fa3b3fd2691da9649dd6abe3cafc7e')

Note: Database.save requires the document to have an id (i.e. a key _id), Database.create does not.

Updating a document

To update an existing document, retrieving the revision is paramount. In the example below, dbdoc contains the key _rev and the builtin dict.update function is used to update the document before saving it.

mydoc = {
    "_id": "mydoc-id",
    "name": "Hello World",
    "type": "Hello World"
}
dbdoc = db.get(mydoc["_id"])
dbdoc.update(mydoc)
print(db.save(dbdoc))
# ('mydoc-id', True, '2-374aa8f0236b9120242ca64935e2e8f1')

Alternatively, one can use Database.rev to fetch the latest revision and overwrite the document

mydoc = {
    "_id": "mydoc-id",
    "_rev": db.rev("mydoc-id"),
    "name": "Hello World",
    "type": "Hello World"
}
print(db.save(mydoc))
# ('mydoc-id', True, '3-d56b14b7ffb87960b51d03269990a30d')

Deleting a document

To delete a document, the docid and rev are needed

docid = "mydoc-id"
print(db.delete(docid=docid, rev=db.rev(docid)))  # Fetch the revision on the go
# True

Working with partitions

For a partitioned database, the couchdb3.database.Partition class offers a wrapper around partitions (acting similarly to collections in Mongo).

from couchdb3 import Server, Database, Partition


client: Server = Server(...)
db: Database = client["some-db"]
partition: Partition = db.get_partition("partition_id")

Partition instances append the partition's ID the document IDs (partition-id:doc-id) for a simpler user interaction, e.g.

doc_id = "test-id"
print(doc_id in partition)  # no need to append the partition's ID
rev = partition.rev(doc_id)
partition.save({
    "_id": doc_id,  # no need to append the partition's ID
    "_rev": rev,
    ...
})

The partition ID will only be appended provided document IDs do not start with partition-id, e.g. the following will work and be equivalent to the previous example

doc_id = "partition_id:test-id"
print(doc_id in partition)
rev = partition.rev(doc_id)
partition.save({
    "_id": doc_id,
    "_rev": rev,
    ...
})