Subsystems (Don't Use)

Technically, these don't work

A Warning

For Python, while it is possible to create a Subsystem class, they don't actually work

Subsystems can be set up similarly to Blueprint Function Libraries with the added expectation of supporting variables:

@unreal.uclass()
class PyEditorSubsystem(unreal.EditorSubsystem):

    value = unreal.uproperty(str)

    def __init__(self):
        super().__init__()
        self.value = 5

    @unreal.ufunction(static=True)
    def basic_function_test():
        print("Running python!")
        pass

Unreal will present it as though it is a valid subsystem in the Blueprint Graph:

Unfortunately, this will result in LogScript warnings when run:

It does provide the functions directly in the right click menu, and they will work during your immediate session:

But it's a trap, the next time you open the Editor it will have a compile error and look like this when you refresh that node:

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Summary: Do Not Use

Subsystems should be avoided until proper support is added for them in Python.