Asynchronous Cloudant / CouchDB interface for Python
Python
Latest commit 4f85e36 Oct 30, 2015 @mikerhodes mikerhodes Merge pull request #56 from gadamc/53626-bump-cloudant-python-version…
…-and-add-deprecation-warnings

Deprecates the 0.5.x branch of the cloudant python library.

readme.md

Cloudant-Python

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This Version is Deprecated

As of 13 October 2015, this development repository is deprecated in favor of the new repository and development branch starting at version 2.0.0a1.

The new version will introduce breaking changes. No attempt was made to follow the API in 0.5.10.

This is the final version of this repository and branch -- 0.5.10.

Please use the new library for your new projects and begin to migrate your old projects that have used versions 0.5.10 and prior.

We will keep 0.5.10 as the latest stable version on PyPI until early 2016, at which time we plan to switch over completely to 2.0.0. Also at that time, this repository will be taken down.

Alpha and Beta versions starting with 2.0.0a1 will be uploaded to PyPI. The latest alpha or beta release may be installed by

pip install --pre cloudant

Note that our new development repository is still pre 2.0.0. As such, we cannot make any guarantees, though we will try, of course, not to introduce new API that will later be removed.

Install

pip install cloudant

Usage

Cloudant-Python is a wrapper around Python Requests for interacting with CouchDB or Cloudant instances. Check it out:

import cloudant

# connect to your account
# in this case, https://garbados.cloudant.com
USERNAME = 'garbados'
account = cloudant.Account(USERNAME)

# login, so we can make changes
login = account.login(USERNAME, PASSWORD)
assert login.status_code == 200

# create a database object
db = account.database('test')

# now, create the database on the server
response = db.put()
print response.json()
# {'ok': True}

HTTP requests return Response objects, right from Requests.

Cloudant-Python can also make asynchronous requests by passing async=True to an object's constructor, like so:

import cloudant

# connect to your account
# in this case, https://garbados.cloudant.com
USERNAME = 'garbados'
account = cloudant.Account(USERNAME, async=True)

# login, so we can make changes
future = account.login(USERNAME, PASSWORD)
# block until we get the response body
login = future.result()
assert login.status_code == 200

Asynchronous HTTP requests return Future objects, which will await the return of the HTTP response. Call result() to get the Response object.

See the API reference for all the details you could ever want.

Philosophy

Cloudant-Python is minimal, performant, and effortless. Check it out:

Pythonisms

Cloudant and CouchDB expose REST APIs that map easily into native Python objects. As much as possible, Cloudant-Python uses native Python objects as shortcuts to the raw API, so that such convenience never obscures what's going on underneath. For example:

import cloudant

# connect to http://localhost:5984
account = cloudant.Account()
db = account.database('test')
same_db = account['test']
assert db.uri == same_db.uri
# True

Cloudant-Python expose raw interactions -- HTTP requests, etc. -- through special methods, so we provide syntactical sugar without obscuring the underlying API. Built-ins, such as __getitem__, act as Pythonic shortcuts to those methods. For example:

import cloudant

account = cloudant.Account('garbados')

db_name = 'test'
db = account.database(db_name)
doc = db.document('test_doc')

# create the document
resp = doc.put(params={
  '_id': 'hello_world',
  'herp': 'derp'
  })

# delete the document
rev = resp.json()['_rev']
doc.delete(rev).raise_for_status()

# but this also creates a document
db['hello_world'] = {'herp': 'derp'}

# and this deletes the database
del account[db_name]

Iterate over Indexes

Indexes, such as views and Cloudant's search indexes, act as iterators. Check it out:

import cloudant

account = cloudant.Account('garbados')
db = account.database('test')
view = db.all_docs() # returns all docs in the database
for doc in db:
  # iterates over every doc in the database
  pass
for doc in view:
  # and so does this!
  pass
for doc in view.iter(descending=True):
  # use `iter` to pass options to a view and then iterate over them
  pass

Behind the scenes, Cloudant-Python yields documents only as you consume them, so you only load into memory the documents you're using.

Special Endpoints

If CouchDB has a special endpoint for something, it's in Cloudant-Python as a special method, so any special circumstances are taken care of automagically. As a rule, any endpoint like _METHOD is in Cloudant-Python as Object.METHOD. For example:

  • https://garbados.cloudant.com/_all_dbs -> Account('garbados').all_dbs()
  • http://localhost:5984/DB/_all_docs -> Account().database(DB).all_docs()
  • http://localhost:5984/DB/_design/DOC/_view/INDEX -> Account().database(DB).design(DOC).view(INDEX)

Asynchronous

If you instantiate an object with the async=True option, its HTTP request methods (such as get and post) will return Future objects, which represent an eventual response. This allows your code to keep executing while the request is off doing its business in cyberspace. To get the Response object (waiting until it arrives if necessary) use the result method, like so:

import cloudant

account = cloudant.Account(async=True)
db = account['test']
future = db.put()
response = future.result()
print db.get().result().json()
# {'db_name': 'test', ...}

As a result, any methods which must make an HTTP request return a Future object.

Option Inheritance

If you use one object to create another, the child will inherit the parents' settings. So, you can create a Database object explicitly, or use Account.database to inherit cookies and other settings from the Account object. For example:

import cloudant

account = cloudant.Account('garbados')
db = account.database('test')
doc = db.document('test_doc')

url = 'https://garbados.cloudant.com'
path = '/test/test_doc'
otherdoc = cloudant.Document(url + path)

assert doc.uri == otherdoc.uri
# True

Testing

To run Cloudant-Python's tests, just do:

python setup.py test

Documentation

The API reference is automatically generated from the docstrings of each class and its methods. To install Cloudant-Python with the necessary extensions to build the docs, do this:

pip install -e cloudant[docs]

Then, in Cloudant-Python's root directory, do this:

python docs

Note: docstrings are in Markdown.

License

MIT, yo.