Question

As I understand it Qt provides 2 main plugin mechanisms:

1. Plugins that extend Qt “Qt Extensions”
2. Plugins that extend applications developed with Qt

I’m interested in developing plugins for my application (2).

I use PySide but can’t find any resources about developing application plugins using PySide/PyQt.

Following the C++ Qt documentation I understand that the application has to use the Q_DECLARE_INTERFACE() macro and the plugins have to use both Q_INTERFACES() and Q_EXPORT_PLUGIN2() macros but I don’t know the code they represent to try and translate it to python. Or is there another way I’ve missed?

Update:

The closest thing to a solution I could find so far is Alex Martelli’s answer to a similar question. Although it looks like it would work I’d rather use an official Qt approach to avoid any cross-platform issues.

Answer 1

I think Qt’s plugin system is intended to allow people to write C++ plugins compiled as binaries. I don’t even know if it’s theoretically possible to write plugins in Python that will use a C++ binary interface like that.

If you want to support Python plugins your best bet would be to use one of the many pure python plugin systems out there. I have written a PySide app that uses YAPSY to load plugin scripts. YAPSY is a very simple, compact plugin module. It’s very easy to include directly in your app as it’s a single file, and is BSD licensed so you can use it commercially. Just search for it on Google. I was even able to package my app using py2exe and still retain the ability to import python source file plugins from a plugin directory.