Python Scripting Settings

You can find preferences for Python Scripting in the Project Settings under the Edit menu.

The top of the window is useful information when looking for help to explain exactly which version of the various components you are using.

Component Versions

Python Scripting bundles with it a copy of the CPython implementation for Python along with a custom build of Python for .NET. For information purposes the Settings panel verifies which version of each is in fact installed. They cannot be changed.

Site Packages

You can add site-packages that will be added to the sys.path to find additional Python modules. Changes are only applied after you restart Unity.

Pip Packages

You can install Python packages using pip for your project. They will be installed inside the Library/PythonInstall/Lib/site-packages folder of the project.

Installing packages with a requirements file

You can store your required Python packages with their versions in a requirements.txt file. To accomodate multiple Unity packages requiring different pip packages, this requirements file is made to be used with pip-tools' compile utility. The same required package may appear more than once, as long both requirements allow the same version ranges. Example :pyside2==5.15.1 and pyside2>=5.15.

If you want to share your Unity project with someone else or you are working in a team, sharing the requirements.txt file will ensure everyone is using the same versions of the same packages. Simply opening a project with a requirements.txt file will automatically install any missing packages, and uninstall unused ones.

Place the requirements file in ProjectSettings/requirements.txt in your Unity project for the Python Scripting package to find it.

For details on creating a requirements file and its uses, please refer to the pip documentation and pip-tools' documentation

Unity will only apply the requirements.txt when you open a project. If you change the requirements.txt while you have a project open (for example, if you update your project from revision control while Unity is running), the Python packages will not update. To apply the new requirements you will need to restart Unity.

Limitations

• You cannot change the internal Python version nor use a virtual environment manager like venv or conda.
• Paths are treated as verbatim strings. You will need to expand environment variables or (on macOS and linux) the ~ denoting the home directory.