Unity-PythonNet

Development Environment

• Windows
• Unity6000.3.5f1 (.NET Framework or both .NET Standard 2.1 and Microsoft.CSharp is required at Api Compatibility Level)
• Python.NET 3.0.5
• Python Embeddable Package 3.11.3

What is this?

This is a sample project that integrates Unity and Python.NET. Pressing the Plot button will display an image of a graph drawn using matplotlib in Python.

Project Structure

+ Assets/
  + Scenes/
    + SampleScene.unity          : Main scene using Unity UI
    + MainView.unity             : Main scene uning UI Toolkit
  + Scripts/
    + PythonLifeCycle.cs         : Python.NET initializer
    + PlotRandom.cs              : Call python script from C# using Python.NET for Unity UI
    + UIEventHandler.cs          : Call python script from C# using Python.NET for UI Toolkit
  + Plugins/
    + Microsoft.CSharp.dll       : Need for .NET Standard 2.1
  + StreamingAssets/
    + python-3.11.3-embed-amd64/ : python runtime
    + myproject/
      + plot_random.py           : python script for graph plot
      + requirements.txt         : a list of items to be installed using pip install

How to add python packages

cd Assets\StreamingAssets\python-3.11.3-embed-amd64\
.\Scripts\pip.exe install matplotlib
.\Scripts\pip.exe freeze > myproject\requirements.txt

Editor Settings: Enter Play Mode Options

Both Domain Reload enabled and disabled are supported with fast Play/Stop.

Domain Reload Enabled

Pros	Cons
Fast Play mode stop	Slightly slower Play mode start
Python code changes are reflected	-
Clean Python state on each Play	-

Domain Reload Disabled

Pros	Cons
Fast Play mode start	Python global state is preserved
Fast Play mode stop	-
Python code changes are reflected (via module reload)	-

Settings: Edit → Project Settings → Editor → Enter Play Mode Options

Known Issues

• PythonEngine.PythonPath is not applied when changing a different PythonEngine.PythonPath after calling PythonEngine.Initialize() / PythonEngine.Shutdown().
  • Restart Unity if you want to set a different PythonEngine.PythonPath.