rbistolfi/nosqlite

NoSQL on top of SQLite

NoSQLite

Super simple NoSQL style data store on top of SQLite written in Python, inspired by http://backchannel.org/blog/friendfeed-schemaless-mysql

>>> from nosqlite import init, Document, Field
>>> init(':memory:')
>>> from nosqlite.view import view

>>> class Movie(Document):
...     indexes = ["director"]
...     name = Field()
...     director = Field()
...
...     @view
...     def count_by_director(self, docs, previous_result=None, is_new=False, deleted=False):
...         """View funcs are called on save and on delete"""
...         if is_new:
...             if not previous_result:
...                 previous_result = {}
...             previous_result.setdefault(self.director, 0)
...             previous_result[self.director] += 1
...         if deleted:
...             previous_result[self.director] -= 1
...         return previous_result


>>> sw1 = Movie(name="Star Wars, A New Hope", director="Lucas")
>>> sw1.save()
>>> sw2 = Movie(name="Star Wars, The Empire Strikes Back", director="Lucas")
>>> sw2.save()
>>> lotr = Movie(name="Lord Of The Rings, The Return of the King", director="Jackson")
>>> lotr.save()

>>> lucas_movies = Movie.find("director", "Lucas")
>>> for movie in lucas_movies:
...     print movie.name
...
Star Wars, The Empire Strikes Back
Star Wars, A New Hope

>>> Movie.count_by_director.latest()
{'Jackson': 1, 'Lucas': 2}

What

• Class based data store
• Attributes marked with Field() are saved
• Data is pickled and stored in SQLite
• "Indexes" are just persistent maps stored in SQLite
• You can only search by indexed fields
• View functions can be used for extra computations

API

init(dbname=":memory:") Init store using dbname as SQLite database

Document Base class for documents

Document.save() Store fields in SQLite

Document.delete() Delete document

Document.find(index, value) Find document

Document.find_one(index, value) Find first match

Document.find_latest(index, value) Find latest match

Document.find_all() You got it :)

Document.is_new() Returns True if doc has not been saved, False otherwise

Document.view_function.latest() Where view_function is a method decorated with @view. Get latest view function return value

Document.view_function.history() Get all the values returned by view_function, orderer by most recent

Field Mark an attribute in a document for being saved

view(func) Declare a method of a Document subclass as view function

License

MIT

Author

Rodrigo Bistolfi [email protected]