Why is using 'C.object.data.uv_layers.remove()' in a loop not removing all UV layers?

Question

After hours of arguing with my code (Trying to eliminate some uv_layers), I'm trying this script directly in the console:

for uv in C.object.data.uv_layers:
    C.object.data.uv_layers.remove(uv)

This is producing unexpected results, including partial, but not complete, deletion of all uv_layers (Uv Map) I would have expected all maps to be deleted. In addition in some cases I get strange errors, with uv_layers names that are not even present in the C.object.data.uv_layers list.

I would like to be sure that we are talking about a bug, in this case I would eliminate the question right away. If not, I'd like to know if I'm doing something wrong.

A simple test is to add a dozen or more uv_layers, manually, and run this code The result:

Answer 1

Try a while loop.

Rather than looping thru a list you are removing from, it is often a better to make a copy of that list and pop and remove until list exhausted.

Using pop() is taking from the end of the list.

>>> me = C.object.data
>>> me
bpy.data.meshes['Suzanne']


>>> uvlayers = me.uv_layers[:]
>>> while uvlayers:
...     me.uv_layers.remove(uvlayers.pop())

Answer 2

Other solution (for completeness) is to walk the list from last element to first one with a for loop. It is more error-prone than copying the full list as suggested by the other answer. Moreover since there will be at most 8 UV Maps the potential speed gain is null.

import bpy

layers = bpy.context.object.data.uv_layers

for uv_layer in reversed(layers):
    layers.remove(uv_layer)