bmuller / twistar

Twistar is an object-relational mapper (ORM) for Python that uses the Twisted library to provide asynchronous DB interaction.

twistar: Asynchronous Python ORM

The Twistar Project provides an ActiveRecord (ORM) pattern interface to the Twisted Project's RDBMS library. This file contains minimal documentation - see the project home page at http://findingscience.com/twistar for more information.

Installation

pip install twistar

Usage

Your database must be one of: MySQL, PostgreSQL, or SQLite. The only DBAPI modules supported by Twistar are: MySQLdb, psycopg2, and sqlite3 - at least one of these must be installed.

Here's the obligatory TL;DR example of creating a User record, assuming that there is a table named "users" with varchar columns for first_name and last_name and an int age column:

#!/usr/bin/env python
from twisted.enterprise import adbapi
from twistar.registry import Registry
from twistar.dbobject import DBObject
from twisted.internet import reactor

class User(DBObject):
     pass

def done(user):
     print "A user was just created with the name %s" % user.first_name
     reactor.stop()

# Connect to the DB
Registry.DBPOOL = adbapi.ConnectionPool('MySQLdb', user="twistar", passwd="apass", db="twistar")

# make a user
u = User()
u.first_name = "John"
u.last_name = "Smith"
u.age = 25

# Or, use this shorter version:
u = User(first_name="John", last_name="Smith", age=25)

# save the user
u.save().addCallback(done)

reactor.run()

Then, finding this user is easy:

def found(users):
    print "I found %i users!" % len(users)
    for user in users:
        print "User: %s %s" % (user.first_name, user.last_name)

u = User.findBy(first_name="John", age=25).addCallback(found)

This is a very simple example - see http://findingscience.com/twistar for more complicated examples and additional uses.

Testing

To run unit-tests you simply require Tox

To run the tests:

tox

By default, the tests are run with the database driver sqlite3. To change this, set the DBTYPE environment variable:

DBTYPE=postgres trial twistar
DBTYPE=mysql trial twistar

You'll need a database named "twistar" for each of those tests (or you can change the dbname, user, etc in the <db type>_config.py file in the tests folder).

Documentation

If you intent on generating API documentation, you will need pydoctor. If you want to generate the user documentation, you will need to install Twisted Lore.

To generate documentation:

make docs

Then open the docs/index.html file in a browser.