use _class_register as a cache for instantiated classes

Signed-off-by: dafnapension <dafnashein@yahoo.com>

Author: dafnapension

src/unitxt/artifact.py

@@ -56,26 +56,14 @@ def get_class_from_artifact_type(type: str):
     module_path, class_name = find_unitxt_module_and_class_by_classname(
         snake_to_camel_case(type)
     )
-    if module_path == "class_register":
-        if class_name not in Artifact._class_register:
-            raise ValueError(
-                f"Can not instantiate a class from type {type}, because {class_name} is currently not registered in Artifact._class_register."
-            )
-        return Artifact._class_register[class_name]
 
     module = importlib.import_module(module_path)
 
     if "." not in class_name:
         if hasattr(module, class_name) and inspect.isclass(getattr(module, class_name)):
-            return getattr(module, class_name)
-        if class_name in Artifact._class_register:
-            return Artifact._class_register[class_name]
-        module_file = module.__file__ if hasattr(module, "__file__") else None
-        if module_file:
-            module = import_module_from_file(module_file)
-
-        assert class_name in Artifact._class_register
-        return Artifact._class_register[class_name]
+            klass = getattr(module, class_name)
+            Artifact._class_register[type] = klass  # use _class_register as a cache
+            return klass
 
     class_name_components = class_name.split(".")
     klass = getattr(module, class_name_components[0])