functional_equivalent.py

for material in bpy.data.materials:

    print("Started "+str(material))
    
    # if the material is transparent use a special shader
    if any((material == bpy.data.materials.get(tm)) for tm in transparentBlocks):
        pass

    # if the material is a light emmitting block use a special shader
    elif any((material == bpy.data.materials.get(lm)) for lm in lightBlocks):
        pass

    # if the material is stationary water, use a special shader
    elif material.name == "Stationary_Water":
        pass
    # if the material is flowing water, use a special shader
    elif material.name == "Flowing_Water":
        pass
    # if the material is slime, use a special shader
    elif material.name == "Slime":
        pass
    # if the material is ice, use a special shader
    elif material.name == "Ice":
        pass
    # if the material is stained glass, use a special shader
    elif material.name in {"Stained_Glass", "Stained_Glass_Pane"}:
        pass
    
    else:
        # use a normal shader
        Normal_Shader(material)

    print("Finished "+str(material))