Differences between Python3 and Python 2 in Rhino 8 Beta

[robertjasoncross]

I am wondering if anyone knows why the rhinocommon library is processed differently between the Python 3 and Python script environments?

Is rhinocommon being re-written for Python 3?

Thanks for any clarity.

[Japhy]

Does this help?

Rhino 8 scripts

@robo Thanks for reporting the crash. I got that fixed just now and should be available in next week’s build. Remember you are opening the older python 2 files in the new editor that opens in Python 3 by default and there are differences between the two that might need adjustments to the scripts. To use Python 2 (IronPython) either add #! python 2 to the top of your script, or renamed the file extension from .py to .py2 I seem to be running the Add layer block.py with no issues here in Pytho…

[robertjasoncross]

Thanks, but not really.

I am just wondering what the differences are between Python 3 implementation and Python 2, as far as Rhinocommon goes. Is it just, read the docs and figure it out? Or, is there a reference to changes being made from v7 to v8?

Best

[eirannejad (Ehsan Iran-Nejad)]

@robertjasoncross

Using RhinoCommon functionality should be virutally indentical in both Python 3 and Python 2. We are in the process of updating the documentation just in case there are any differences. You should be able to copy/paste your exising python 2 code into a new script component with minor changes mostly related to differences in python versions e.g. print is a function in python 3, or some standard libraries names have changed.

On the implementation side, and internally however, Python 3 and 2 are VERY different.

Let me know if you have specific questions in any of these areas.

[eirannejad (Ehsan Iran-Nejad)]

The error that you shared seems to be a bug. I have logged it here, and will get that fixed

RH-77315 Point3d is missing .Clone() in python 3

[robertjasoncross]

I am just trying to understand the issues as shown in the image above. Same code, p3 throws an error, Py2 does not. I have no problem understanding Python 2 and 3 context and the script component, etc. I am just wondering why the two are responding differently. Is there a different way we are supposed to clone points in py3/rhino8?

Thanks.

[eirannejad (Ehsan Iran-Nejad)]

Okay this is an odd one. .Clone() is an explicit method on Point3d and hence you will not be able to call it directly in C# or Python 3. I’m not sure why IronPython allows doing that but then again IronPython did a lot of sketchy things.

This will do the job for now. I’ll continue inspecting this and see what I can do

in Python 3

import System

System.IClonable.Clone(origin)

In C#

using System;

clone = ((System.ICloneable)origin).Clone();

[robertjasoncross]

Thanks for the help.
That threw another error. I guess I will just have to solve it with code changes.

Thanks again.

[stevebaer]

@eirannejad

IronPython did a lot of sketchy things.

Well, Point3d is IClonable so that is a bit of a gray area on how python implementations decide to interpret interfaces. I would recommend using the copy constructor in both Py2 and Py3

import Rhino.Geometry as rg
clone = rg.Point3d(origin)

[eirannejad (Ehsan Iran-Nejad)]

Are you running the netcore or netframework Rhino? If you haven’t played with settings it’s probably netcore. I’m not getting this error on my machine but till test.

[robertjasoncross]

Not sure of the difference. I have only installed the beta as default

[eirannejad (Ehsan Iran-Nejad)]

@robertjasoncross Ok. I’d follow Steve’s advice above and use the copy constructor.