Import Python Dependencies from current script/addon directory. (Filepath shows up as /script.py, or blender install)

Question

I'm trying to import a github python directory, which is not on PyPi, and I am attempting to develop an addon for blender. I cannot use the method which automatically downloads dependencies because of this, so I have to work within a folder that acts as my addon's "zip" folder.

However the alternative method to import dependencies requires a direct filepath, so I need to get the working file directory of the addon/script.py file while testing the addon in blender (so I don't have to reinstall the addon for every minor change):

path = pathlib.Path(bpy.data.filepath)
myProjects_dir = path.parent.parent.parent.resolve() 
myProjects_dir = str(myProjects_dir)
print(myProjects_dir)

but this just prints the blender install directory folder. Every variation of this using abspath or os.path.realpath, which end up either being a blank line, /, or /Script.py, with no actual path or parent directory listed.

How am I supposed to actively write a blender addon if I cannot test it in the editor with one click? Am I really expected to have to install and uninstall the addon every time?

Answer 1

You need to understand Blender's Directory Layout and how to access it from Python. Your specific case requires the USER path with the scripts/addons path appended followed by the path to your addon. Something along these lines:

import bpy
import pathlib

USER  = pathlib.Path(bpy.utils.resource_path('USER'))
ADDONS = USER / 'addons'
MYADDON = ADDONS / 'my_addon_name'  # Replace with the name of your addon

path_string = str(MYADDON)

Many examples will use os rather than pathlib but since Python 3.4 pathlib is preferred for simple path manipulation because it is object oriented and less heavy weight.