FDS: Add typing module with array types definitions (#2796)

datasets/flwr_datasets/common/typing.py

@@ -0,0 +1,26 @@
+# Copyright 2023 Flower Labs GmbH. All Rights Reserved.
+#
+# 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.
+# ==============================================================================
+"""Flower Datasets type definitions."""
+
+
+from typing import Any, List
+
+import numpy as np
+import numpy.typing as npt
+
+NDArray = npt.NDArray[Any]
+NDArrayInt = npt.NDArray[np.int_]
+NDArrayFloat = npt.NDArray[np.float_]
+NDArrays = List[NDArray]