How to change Texture properties via python?

Question

Changing texture data properties via python seem impossible because the properties are inherited from the texture Type

for example texture.noise_scale don't exists yet if texture.type is currently "IMAGE" because texture.noise_scale is a child property of some subclass types

so if you are starting from an image type the following code won't be able to work

texture = bpy.data.textures["MyImgTexture"]
texture.type = "MARBLE" #changing type
texture.noise_scale = 5.5 #changing noise scale from this new type 

What can we do to refresh the child properties? bpy.context.view_layer.update() won't help here

Answer 1

Recast the type

For objects that can have their types changed can recast the types using type_recast

>>> tex.type_recast(
type_recast()
.. method:: type_recast()
Return a new instance, this is needed because types
such as textures can be changed at runtime.
:return: a new instance of this object with the type initialized again.
:rtype: subclass of :class:`bpy.types.bpy_struct`

try it out in console.

>>> tex = D.textures.new("Tex", 'STUCCI')
>>> tex.name
'Tex'

>>> tex.type
'STUCCI'

>>> tex.image
Traceback (most recent call last):
  File "<blender_console>", line 1, in <module>
AttributeError: 'StucciTexture' object has no attribute 'image'

>>> tex.type = 'IMAGE'
>>> foo = tex.type_recast()
>>> foo.image is None
True

>>> foo.name
'Tex'

>>> foo
bpy.data.textures['Tex']

Notice too the two instances keep there type

>>> str(tex)
'<bpy_struct, StucciTexture("Tex") at 0x7f89ff16b448>'

>>> str(foo)
'<bpy_struct, ImageTexture("Tex") at 0x7f89ff16b448>'

btw, if while checking this out in console the properties area is open on same screen, it is being done automatically for us.

Answer 2

It's a bit unintuitive but refetching the Texture after changing the type works for me :

import bpy

texture = bpy.data.textures["Texture"]
texture.type = "MARBLE" #changing type
texture = bpy.data.textures["Texture"] # This one has noise_scale attribute
texture.noise_scale = 2  #changing noise scale from this new type