Fusion September Release Will Include Python Version Update to 3.11

[prainsberry]

In the upcoming release in September, we are upgrading the Python version used in Fusion from 3.9 to 3.11.

If you write or use any Python apps delivered as .pyc files, this change will break them!

This change will impact any add-ins delivered as compiled Python modules (.pyc files). Compiled modules are only compatible with the minor release version of Python that was used to create them, which means Add-ins compiled with Python 3.9 will fail to load with the new version (3.11). If the add-in folder includes the .py source files, it's not a problem since Python will automatically recompile them to create new .pyc files, so this only impacts add-ins that only deliver .pyc files or that rely on libraries that only include the .pyc files.

The change will happen in September, but with this release, Fusion will begin notifying users if they have any scripts or add-ins that use .pyc files. The add-in will continue to normally run in the July release, but the warning lets the user know they will need to get an updated version of the add-in when the September release is available.

Click here for more information

There are two options to begin this process:

• Sign up for the Fusion Insider Program.  This should give you access to the March release about ~2 weeks before public launch.  This will have the new version of Python and you can compile and test your new add-in version.
• Install a local copy of Python 3.11 and compile your code.  The challenge here is that you will not be able to test directly in the current version of Fusion 360 as 3.9 compiled .pyc files will not run in the 3.11 version.  If it is absolutely necessary, you could at least ensure code compatibility and that there are not build failures before the Early Access version (above) is available.

If you distribute your app through the App Store it is important that you begin the submission process as soon as possible after the Early Access version is available to ensure there is enough time to create installers, test, sign and publish your app.  

The App Store team is aware of the issue and any app submissions (new or updated) that fall into this category will be held for release until the day the new Fusion version goes live. 

Some notes on Python 3.11

In general most scripts and add-ins written with python 3.9 should be compatible, but you should still consult the documentation and test when the new version is available. 

There are also a few nice features that have been added in the  Python 3.10 and 3.11 updates.

https://www.python.org/downloads/release/python-3100/

https://www.python.org/downloads/release/python-3110/