What is link_kigadgets_to_pcbnew doing for you?

The KiCad application comes with its own isolated version of python. It is not designed to install any new packages like this one. Furthermore, its python API is not installed in a place that your external python or pip can find.

link_kigadgets_to_pcbnew creates a bidirectional link, telling kigadgets (this package) and pcbnew.py (their builtin C++ wrapper) where to find each other. The script all does this for you.

GUI startup script

First, it writes an initialization script for the pcbnew GUI’s application terminal. It runs automatically when the shell opens and looks like this

# File (for example): /home/myself/.config/kicad/PyShell_pcbnew_startup.py
import sys
sys.path.append("/env/from_which/you_called/link_kigadgets/site-packages")
from kigadgets.board import Board
pcb = Board.from_editor()  # pcb is now a global variable in the terminal

Effect: You can now use kigadgets features in your GUI terminal. Quick 3-line scripts can be quite useful (examples below).

Expose kigadgets to all action plugins

Second, the script exposes kigadgets to the pcbnew GUI action plugin environment. It does this by linking this package into the “kicad/scripting/plugins” directory.

Effect: You can now use kigadgets when developing action plugins.

Expose pcbnew to external pythons

Third, it exposes KiCad’s pcbnew.py to your external python environment. The path is stored in a file called .path_to_pcbnew_module, which is located in the kigadgets package installation. Since it is a file, it persists after the first time. You can override this in an environment variable PCBNEW_PATH.

For import pcbnew to work from outside the GUI, you must first import kigadgets.

Effect: You can now use the full KiCad built-in SWIG wrapper, the kigadgets package, and any non-GUI plugins you are developing outside of the pcbnew application. It is useful for batch processing, remote computers, procedural layout, continuous integration, and use in other software such as FreeCAD and various autorouters.