jaraco.modb 2.1

MongoDB Object DataBase (MODB) for Python objects

Contents

• Overview

• Usage

• Features

• Changes

  • 2.1

  • 2.0

  • 1.2

  • 1.1

  • 1.0.4

  • 1.0

Overview

jaraco.modb is a small, pure-Python library for persisting Python objects to MongoDB.

jaraco.modb is written by Jason R. Coombs. It is licensed under an MIT-style permissive license.

You can install it with easy_install jaraco.modb or grab the source code from the mercurial repository.

Usage

jaraco.modb facilitates using jsonpickle to produce MongoDB-friendly representations of pickleable Python objects for easy storage in a MongoDB database.

One may simply encode and decode Python objects to MongoDB BSON-friendly representations:

class MyObject(object):
    def __init__(self, val):
        self.val = val

import jaraco.modb
import pymongo
mongo_collection = pymongo.Connection().mydb.mycollection
val = MyObject(3)
# save the object to the DB
id = mongo_collection.save(jaraco.modb.encode(val))
# retrieve the object from the DB
new_val = jaraco.modb.decode(mongo_collection.find_one(id))
assert isinstance(new_val, MyObject)
assert new_val.val == 3

Features

Reduce Support

jsonpickle 0.4 doesn’t support the reduce protocol out of the box. jaraco.modb provides a handy way to do this with the SimpleReduceHandler:

@jaraco.modb.handlers.SimpleReduceHandler.handles
class MyUnicode(unicode):
    def __reduce__(self):
        return MyUnicode, (unicode(self),)

Note that you must provide the __reduce__ method as the built-in reduce method returns a function that jsonpickle cannot serialize.

Changes

2.1

• Added convenience method for decorating functions with the SimpleReduceHandler.

2.0

• Removed initializer function (jaraco.modb.init()). Clients should remove that call (if present) before upgrading to 2.0.

1.2

• Now store naive and UTC datetimes naturally in MongoDB.

• The encoder/decoder now subclasses the jsonpickle classes to more efficiently handle binary strings.

1.1

• Added proper support for datetime objects.

• Added support for OrderedDictionaries.

1.0.4

• Removed requirement to call jaraco.modb.init() to initialize.

1.0

• Initial release