Miscellaneous add-on scripting questions

Coding Python Support
1

Hi,

lately I’ve been wanting to start learning scripting so I’ve been going through a few scripts (mostly exporters) and I’ve had a few questions.

if __name__ == "__main__":
    register()

I’ve seen these pop-up in the scripts that I was reading and I’m not quite sure why it’s required… I’d also like to know what exactly I should include in the register()/unregister() functions

Also looking at the povray exporter

if "bpy" in locals():
    import imp
    imp.reload(ui)
    imp.reload(render)

else:
    import bpy
    from bpy.props import *
    from render_povray import ui
    from render_povray import render

There’s this bit of code which I’m left slightly puzzled by. Why not just do regular imports? what is “imp”? the import module? I’ve also read a post or two mentioning that one should not use “from bpy.props import *” is this true?

Thank you and happy blending! :slight_smile:

2

from what i gather when you are doing a console session to figure out how to piece together your script you can happily do a

from whatevermodule import *

but if you are writing a script that you wish to distribute, then things are a little different. You really want to have control over what you are importing. By importing * you are in danger of polluting namespace

maybe a more gratifying set of answers is found here :

3

Bear in mind that many of the scripts in the Blender 2.5x source tree have not been updated for later simplifications in the API.

For an introduction to Blender scripting that is as current as I’m aware, try here http://en.wikibooks.org/wiki/Blender_3D:_Noob_to_Pro/Advanced_Tutorials/Python_Scripting/Introduction_New.

4

Oh right, I didn’t know there was a difference between “import bpy” and “from bpy import *”

As for the addon I’m writing it’s more of a “writing” exercise than anything else but I’d still like to write it so it would be something that could be handed out to others.

So far it really doesn’t do much but in case you’re curious here it is:

@Ido: thanks it answered a few of my questions :slight_smile: