In the previous chapter, we talked about why Python can be useful, and how to follow this training.

Here, we’ll see how to configure a UE project to be able to run Python.

Table of contents

Introduction

Using Python inside of Unreal is quite new. It’s supported on UE 4.26 and newer versions, but it’s still an experimental feature in development. It was possible on older version of UE as well, but it was not something developed by Epic.

The way it works is simple

• The Python Interpreter (python.exe) is packaged inside of UE, so you don’t need to install Python on your machine. However if you have Python installed, don’t worry it’s not a problem, UE will use that one:

  

  <aside> ❔ The Python Interpreter is a program that execute Python Just In Time (JIT), meaning there is no need to compile your program, it will be interpreted/compiled when running.

  </aside>

• To execute Python from UE, a plugin called Python Editor Script Plugin is provided. This is a C++ plugin that will add features (blueprint nodes, editor menus, …) but eventually will just call python.exe.

Running Python from UE is super useful, but you should know what you can do and what you cannot.

• Python functionalities only work in editor and on Windows. You cannot run Python from the game!
• Because UE is made in C++, UE developers are creating a lot of Python bindings so that we can use UE features from Python (think of bindings as bridges between 2 languages). We don’t really care about that, but it mean few things:
  • Not everything is as well documented as the C++ functionalities
  • Some things may not work as well as in C++, because Python support is still new, so it’s experimental
  • Some things are just not possible in Python yet because there was no binding with C++ created

Now, let’s configure our UE project.

Setup

Start with a UE 5.0 project, or get the one available in Getting the project files.

To run Python code in UE, we have to make sure the Python Editor Script Plugin plugin is enabled. Go in Edit > Plugins and check it. Then restart UE.