Add iDynTree loader

Author: GiulioRomualdi

robot_descriptions/loaders/idyntree.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+# Copyright 2022 Giulio Romualdi
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+Load a robot description in iDynTree.
+"""
+
+from importlib import import_module  # type: ignore
+
+import idyntree.swig as idyn
+
+
+def load_robot_description(description_name: str) -> int:
+    """
+    Load a robot description in iDynTree.
+
+    Args:
+        description_name: Name of the robot description.
+
+    Returns:
+        Identifier of the robot in iDynTree.
+    """
+    module = import_module(f"robot_descriptions.{description_name}")
+    if not hasattr(module, "URDF_PATH"):
+        raise ValueError(f"{description_name} is not a URDF description")
+
+    model_loader = idyn.ModelLoader()
+    model_loader.loadModelFromFile(module.URDF_PATH)
+    robot = model_loader.model().copy()
+    return robot