Remove from CollectionProperty

Question

I am using the the CollectionProperty class to store a list of properties, so something like this:

class MyPropertyGroup(bpy.types.PropertyGroup):
    name = bpy.props.StringProperty(name="Property Name", default="Something")
    value = bpy.props.IntProperty(name="Property Name", default=22)

bpy.utils.register_class(MyPropertyGroup)
bpy.types.World.my_collection_prop = bpy.props.CollectionProperty(type=MyPropertyGroup)

Then in an Operator I am calling the add() method to create additional properties:

class MyOperator(bpy.types.Operator):
    # some irrelevant code here...

    def execute(self, context):
        my_prop = context.world.my_collection_prop.add()
        my_prop.name = "test"
        my_prop.value = 123

Now my problem is doing the opposite of add().

How do I go about removing an instance from a CollectionProperty?

Answer 1

As I was about to click the button to post this question, I realized maybe the CollectionProperty class extends/has the same methods as a dictionary or list. Anyway, with a little trial and error I found that it does (sort of).

To remove a single element:

context.world.my_collection_prop.remove(2)

To clear the whole collection:

context.world.my_collection_prop.clear()

I really don't understand how details like this get left out of the Blender API documentation.

Answer 2

Use the CollectionProperty.find(name) to find the index of the item to remove. Then remove the item with remove(index) method. For example:

def remove_item(collection, item):
     collection.remove(collection.find(item.name))

Then use like this:

remove_from_collection(context.world.my_collection, my_item)