Learn to write post processing script

[3DukeEngineering 2]

I am interested in learning how to write a script for post processing gcode and then implementing it into Cura. 
 

Can anyone recommend any good resources or examples to review that are specific to this?

 

I know there is probably plenty online about script writing in general, but given the wide spread application I’d like to avoid picking up a degree just to do what I want.

 

Reason being, I have just build my first IDEX printer, and having a fleet of Ultimakers, I am an avid Cura user. But the way Cura handles certain things in relation to tool changes, is just not very smart/efficient.

 

a couple of thing I would like to do with a script:

 

1) edit the extruder 1 + 2 start gcode the first time it’s used in the gcode.

 

2) Remove every second M109 command after every T0/T1 command

 

3) Increase the feedrate for the first G0 move after every T0/T1 command

[GregValiant 1,142]

I'm a self-taught Visual Basic coder.  Unfortunately for me, knowing VB in the Cura world is like knowing Latin.  It's not real helpful.  Moving from my very dated knowledge of "Visual Basic for Applications" to "VB.Net" and Visual Studio was enough of a problem.  I have created a modest little Windows app (Greg's Toolbox) that among other things will switch between, and control, up to 10 printers.

 

Reviewing some post-processing plugins (PauseAtHeight.py and SearchAndReplace.py in particular) helped me to understand a bit about how they work to find something in the gcode stream, and then to insert new code.  It gave me just enough of an understanding of Python for me to customize them to suit my needs.  For myself and what I do, writing post-processors in VB.Net didn't require any knowledge of Python or Cura as I just deal with gcode files after they are generated.  Splicing two files together and creating the transition code, altering retraction distance in a file, removing Z-hops, changing a file created for 2.85mm filament to 1.75mm filament (or vice versa) are some of the utilities in the app.  Not stuff that would be terribly useful to anyone else, but I've been stuck in the house a lot.