Reference/Release Notes/2.80/Python API

= Blender 2.80: Python API Changes =

Blender 2.80 is an API breaking release. Addons and scripts will need to be updated to run on 2.80, both to handle the new features and adapt to changes to make the API more consistent and reliable.

Addon API
Module and class registration has been changed, all addons need to be updated to handle these.

Scene and Object API
The new view layers, collections, selection and dependency graph systems require updates to scripts.

Mesh API
A few changes were made to the Mesh API, mainly the data structures for triangles tessellation.

Preferences API
To match the redesigned and reorganized Preferences UI, the Python API got updated too.

User Interface API
New toolbar, property layouts and icons require addon updates.

Adapting Your Addon for the 2.8 User Interface
Blender 2.8 has a new UI that requires your addon to adapt.

Draw API
Blender was upgraded to the OpenGL core profile, which affects addons.

Timer API
A new API to run functions in specific time intervals.

Animation & Rigging API
A number of utility methods related to animation and rigging have been added.

Helper Modules
Various helper Python modules have been added, removed or changed.

Renaming
A few terms have been renamed in the user interface, and the Python API follows along. The main ones are:
 * Lamp to Light
 * Group to Collection
 * Dupli to Instance
 * Render Layer to View Layer
 * User Preferences to Preferences

Keyword Only Arguments
All optional arguments must be given as keywords and cannot be passed by position:

2.7x

2.8x

Matrix Multiplication
Matrix multiplication previously used *, scripts should now use @ for multiplication (per PEP 465). This applies to:
 * Vector * Vector
 * Quaternion * Vector
 * Matrix * Vector
 * Vector * Matrix
 * Matrix * Matrix

Note: In the future * will be used for element-wise multiplication 2.7x:

2.8x:

Using the 2.7x syntax in 2.80 or later will result in this error:

In Place Matrix Multiplication
Note that mat_a *= mat_b did not change the original matrix, now in 2.8 it does (matching other types - Vector and Python lists for example).

Noting this since it could be a breaking change for scripts that relied on it creating a new matrix, especially if in cases where a matrix is passed as a function argument and changed to it aren't expected.

Importing Text
The ability to import Blender text data blocks as modules has been removed.

If you need to get a text data-block as a module use: