Implementing a Plugin System in Python

Question

I am writing an application (a server wrapper for Minecraft) that I wish to make extensible with plugins. I have a system in place that works, however I think that in the long r

Answer 1

I would suggest to use setuptools, because plugins are linked eventually to the management of the sys.path list:

http://peak.telecommunity.com/DevCenter/PkgResources

In the long run, a distribution/packaging based solution like setuptools would always be a solid choice since:

• you have to load plugins without conflicts or missing requirements,
• even if the plugins loaded depend themselves on other dynamic dependencies, and
• you have to keep the list of available plugins updated as packages are installed and removed.

Answer 2

Having written quite a few different plugin architectures in different platforms and languages, I will say that you are pretty much on track with how most plugins systems are written.

Basically what it boils down to, is your host and your plugin need to have some kind of common contract to work with; in other words, your host needs to know enough about your plugin that it can pass along or share whatever common resources the plugin will need, and the plugin needs to know enough about the host to interact with those resources.

Implementing this using a base class and a derived class as you have done is a very common methodology.