How to change material instance parameter by Python?

[Skell_VR]

How to change material instance parameter by Python?
I want to when I excecute Python,my material instance parameter can auto change

This is my python code but it’s not work

import unreal

@unreal.uclass()
class GetMaterialInstanceConstant(unreal.MaterialInstanceConstant):
pass
@unreal.uclass()
class GetEditorProperty(unreal.MaterialInstanceConstant):
pass
@unreal.uclass()
class GetParameterInfo(unreal.MaterialInterface):
pass

MaterialParameterInfo=GetParameterInfo
print(MaterialParameterInfo)

Diffuse_Main_Map_Brightness=True

def get_scalar_parameter_value(Diffuse_Main_Map_Brightness):
return float(2.0)

---

[knapeczadam]

import unreal

editor_util = unreal.EditorUtilityLibrary()
material_util = unreal.MaterialEditingLibrary()

selected_assets = editor_util.get_selected_assets()

# if len(selected_assets) == 1:
    # selected_assets[0] ...

for asset in selected_assets:
    if asset.get_class().get_name() == "MaterialInstanceConstant":
        material_util.set_material_instance_scalar_parameter_value(asset, "Diffuse Main Map Brightness", 42)