Custom Resource: fields recognized by the editor but not by scripts

[simpgamedev]

Godot Version

4.2.1

Question

Why are the fields of my custom resource unknown in scripts but show up in the editor?
I assign instances of my custom resource “Item” to export variables in the editor.
But when trying to access their fields, e.g. field “type” I get the error
Invalid get index 'type' (on base: 'Resource').

class_name Item
extends Resource

@export var type = 0
@export var levels = {}

func _init(_type, _levels):
	type   = _type
	levels = _levels

Instance of custom resource saved as 2100.tres

[gd_resource type="Resource" script_class="Item" load_steps=2 format=3 uid="uid://bkt04gatgdrdb"]

[ext_resource type="Script" path="res://types/item.gd" id="1_mpm58"]

[resource]
script = ExtResource("1_mpm58")
type = 2100
levels = {}

[mrcdk]

Don’t use required parameters in Object._init() or the Resource will fail to load.

[simpgamedev]

Many thanks. I changed the _init function like this:

func _init(_type=0, _levels={}):
	type   = _type
	levels = _levels

I overlooked that hint in the tutorial since it worked somehow in the editor
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