Debian is currently shipping GIMP 2 without Python support, since Python 2 has been dropped.
But I found I was able to create a pure-Python wrapper around libgimp2 in Python 3. This required the creation of my own wrappers around GEGL and BABL as well, plus some parts of GLib/GObject.
The result so far has been sufficient to reimplement some simple plugins. And the amount of code needed has been much less than the 30,000 or so lines of C required to implement the pygimp Python interface.
You can check out my work (such as it is) below.