reobject

reobject is an ORM layer for your objects. It allows you to track and query objects at runtime using a familiar query langauge inspired by Django ORM.

Note: reobject is NOT a database ORM. It keeps track of regular objects in the memory.

This is highly experimental code, and not safe for production.

Installation

reobject supports Python 3 only.

pip install reobject

Example usage

from reobject.models import Model, Field

class Book(Model):
    title = Field()
    authors = Field()
    price = Field()

>>> # Create a bunch of objects
>>> Book(title='The C Programming Language', authors=['Kernighan', 'Ritchie'], price=52)
>>> Book(title='The Go Programming Language', authors=['Donovan', 'Kernighan'], price=30)

>>> Book.objects.all()  # All books
[Book(title='The C Programming Language', authors=['Kernighan', 'Ritchie'], price=52),
 Book(title='The Go Programming Language', authors=['Donovan', 'Kernighan'], price=30)]

>>> Book.objects.filter(price__lt=50).values('title')  # Titles of books priced under $50
[{'title': 'The Go Programming Language'}, {'title': 'The C Programming Language'}]

>>> # Titles of books co-authored by Brian Kernighan
>>> Book.objects.filter(authors__contains='Kernighan').values_list('title', flat=True)
['The Go Programming Language', 'The C Programming Language']

Features

• Elegant data-model syntax inspired by Django ORM.
• Class-level model fields, out of the box object protocols, pretty reprs; powered by attrs.
• Advanced query language and chainable querysets. Read the QuerySet API docs.
• Transactions. See example.
• Many-to-one model relationships. See example
• [TBA] Attribute indexes for fast lookups.

Crunching Design Patterns

| Pattern | Description | Pure Python | reobject | |:-------------:|:--------------------------------------------------------:|:--------:|:-----------:| | Flyweight | Reuse existing instances of objects with identical state | Link | Link | | Memento | Transactional rollback of an object to a previous state in case of an exception | Link | Link | | Prototype | Create clones of a prototype without instantiation | Link | Link | | Singleton | Restrict a class to provide only a single instance | Link | Link | | Facade | Encapsulate a complex subsystem within a single interface object | Link | Link | | Flux | Event-driven state management inspired by Facebook Flux | Link | Link |

_{<b>Note:</b> Some of the examples above may be inaccurate. The idea is to demonstrate what <i>reobject</i> is capable of. Pull requests are most welcome.}

Contributing

Want to help? You can contribute to the project by:

• Using reobject in your projects, finding bugs, and proposing new features.
• Sending pull requests with recipes built using reobject.
• Trying your hand at some good first bugs.
• Improving test coverage, and writing documentation.