Documentation

http://packages.python.org/python-stdnet/

Dowloads

http://pypi.python.org/pypi/python-stdnet/

Source

http://code.google.com/p/python-stdnet/

Keywords

server, database, cache, redis, orm

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An object relational mapper fro remote data structures.

The data is owned by different, configurable back-end databases and it is accessed using a light-weight Object Relational Mapper (ORM) inspired by Django and SQLAlchemy. The source code is hosted at google code while Documentation and Downloads are available via PyPi.

• You need access to a Redis server.
• redis-py version 2.0 or higher.

To install, download, uncompress and type:

python setup.py install

otherwise use easy_install:

easy_install python-stdnet

or pip:

pip install python-stdnet

To know whech version you have installed:

>>> import stdnet
>>> stdnet.__version__
'0.3.2'

At the moment, only redis back-end is available, so to run tests you need to install redis. Once done that, launch redis and type:

>>> import stdnet
>>> stdnet.runtests()

otherwise from the package directory:

python runtests.py

Running tests with the above commands assumes your Redis server is running on the same machine.

StdNet comes with two default settings.

>>> from stdnet.conf import settings >>> settings.__dict__ {'DEFAULT_BACKEND': 'redis://127.0.0.1:6379/?db=7', 'DEFAULT_KEYPREFIX': 'stdnet'}

If your redis server runs on a different machine, you need to setup a script file along these lines:

if __name__ == '__main__':
    from stdnet.conf import settings
    settings.DEFAULT_BACKEND = 'redis://your.server.url:6379/?db=10'
    import stdnet
    stdnet.runtests()

Backend data-stores provide the backbone of the library, while the Object Relational Mapper the syntactic sugar. Currently the list of back-ends is limited to

• Redis. Requires redis-py.
• Local memory (planned). For testing purposes.
• CouchDB (planned). Requires couchdb-python.

Only Redis is operational.

The module stdnet.orm is a lightweight ORM:

from stdnet import orm

class Base(orm.StdModel):
    name = orm.SymbolField(unique = True)
    ccy  = orm.SymbolField()

    def __str__(self):
        return str(self.name)

    class Meta:
        abstract = True

class Instrument(Base):
    type = orm.SymbolField()

class Fund(Base):
    description = orm.CharField()

class PositionDescriptor(orm.StdModel):
    dt    = orm.DateField()
    size  = orm.FloatField()
    price = orm.FloatField()
    position = orm.ForeignKey("Position")

class Position(orm.StdModel):
    instrument = orm.ForeignKey(Instrument, related_name = 'positions')
    fund       = orm.ForeignKey(Fund)
    history    = orm.ListField(model = PositionDescriptor)

    def __str__(self):
        return '%s: %s @ %s' % (self.fund,self.instrument,self.dt)

Register models with backend:

orm.register(Instrument,'redis://localhost/?db=1')
orm.register(Fund,'redis://localhost/?db=1')
orm.register(PositionDescriptor,'redis://localhost/?db=2')
orm.register(Position,'redis://localhost/?db=2')

And play with the API:

>>> f = Fund(name="pluto,description="The super pluto fund",ccy="EUR").save()
Fund: pluto

This software is licensed under the New BSD License. See the LICENSE file in the top distribution directory for the full license text.