Python Dependency Injection Framework

Question

Is there a framework equivalent to Guice (http://code.google.com/p/google-guice) for Python?

Answer 1

Spring Python is an offshoot of the Java-based Spring Framework and Spring Security, targeted for Python. This project currently contains the following features:

• Inversion Of Control (dependency injection) - use either classic XML, or the python @Object decorator (similar to the Spring JavaConfig subproject) to wire things together. While the @Object format isn't identical to the Guice style (centralized wiring vs. wiring information in each class), it is a valuable way to wire your python app.
• Aspect-oriented Programming - apply interceptors in a horizontal programming paradigm (instead of vertical OOP inheritance) for things like transactions, security, and caching.
• DatabaseTemplate - Reading from the database requires a monotonous cycle of opening cursors, reading rows, and closing cursors, along with exception handlers. With this template class, all you need is the SQL query and row-handling function. Spring Python does the rest.
• Database Transactions - Wrapping multiple database calls with transactions can make your code hard to read. This module provides multiple ways to define transactions without making things complicated.
• Security - Plugin security interceptors to lock down access to your methods, utilizing both authentication and domain authorization.
• Remoting - It is easy to convert your local application into a distributed one. If you have already built your client and server pieces using the IoC container, then going from local to distributed is just a configuration change.
• Samples - to help demonstrate various features of Spring Python, some sample applications have been created:
  • PetClinic - Spring Framework's sample web app has been rebuilt from the ground up using python web containers including: CherryPy. Go check it out for an example of how to use this framework. (NOTE: Other python web frameworks will be added to this list in the future).
  • Spring Wiki - Wikis are powerful ways to store and manage content, so we created a simple one as a demo!
  • Spring Bot - Use Spring Python to build a tiny bot to manage the IRC channel of your open source project.

Answer 2

I like this simple and neat framework.

http://pypi.python.org/pypi/injector/

Dependency injection as a formal pattern is less useful in Python than in other languages, primarily due to its support for keyword arguments, the ease with which objects can be mocked, and its dynamic nature.

That said, a framework for assisting in this process can remove a lot of boiler-plate from larger applications. That's where Injector can help. It automatically and transitively provides keyword arguments with their values. As an added benefit, Injector encourages nicely compartmentalized code through the use of Module s.

While being inspired by Guice, it does not slavishly replicate its API. Providing a Pythonic API trumps faithfulness.