Add NumpyRandomSeedSetter (#526)

src/coola/random/__init__.py

@@ -2,8 +2,14 @@
 
 from __future__ import annotations
 
-__all__ = ["BaseRandomSeedSetter", "RandomRandomSeedSetter", "TorchRandomSeedSetter"]
+__all__ = [
+    "BaseRandomSeedSetter",
+    "NumpyRandomSeedSetter",
+    "RandomRandomSeedSetter",
+    "TorchRandomSeedSetter",
+]
 
 from coola.random.base import BaseRandomSeedSetter
+from coola.random.numpy_ import NumpyRandomSeedSetter
 from coola.random.random_ import RandomRandomSeedSetter
 from coola.random.torch_ import TorchRandomSeedSetter

src/coola/random/numpy_.py

@@ -0,0 +1,43 @@
+r"""Implement a random seed setter for NumPy."""
+
+from __future__ import annotations
+
+__all__ = ["NumpyRandomSeedSetter"]
+
+from unittest.mock import Mock
+
+from coola.random.base import BaseRandomSeedSetter
+from coola.utils import check_numpy, is_numpy_available
+
+if is_numpy_available():
+    import numpy as np
+else:  # pragma: no cover
+    np = Mock()
+
+
+class NumpyRandomSeedSetter(BaseRandomSeedSetter):
+    r"""Implement a random seed setter for the library ``numpy``.
+
+    The seed must be between ``0`` and ``2**32 - 1``, so a modulo
+    operator to convert an integer to an integer between ``0`` and
+    ``2**32 - 1``.
+
+    Example usage:
+
+    ```pycon
+
+    >>> from coola.random import NumpyRandomSeedSetter
+    >>> setter = NumpyRandomSeedSetter()
+    >>> setter.manual_seed(42)
+
+    ```
+    """
+
+    def __init__(self) -> None:
+        check_numpy()
+
+    def __repr__(self) -> str:
+        return f"{self.__class__.__qualname__}()"
+
+    def manual_seed(self, seed: int) -> None:
+        np.random.seed(seed % 2**32)

tests/unit/random/test_numpy.py

@@ -0,0 +1,46 @@
+from __future__ import annotations
+
+from unittest.mock import patch
+
+import pytest
+
+from coola.random import NumpyRandomSeedSetter
+from coola.testing import numpy_available
+from coola.utils import is_numpy_available
+
+if is_numpy_available():
+    import numpy as np
+
+###########################################
+#     Tests for NumpyRandomSeedSetter     #
+###########################################
+
+
+@numpy_available
+def test_numpy_random_seed_setter_repr() -> None:
+    assert repr(NumpyRandomSeedSetter()).startswith("NumpyRandomSeedSetter(")
+
+
+@numpy_available
+def test_numpy_random_seed_setter_str() -> None:
+    assert str(NumpyRandomSeedSetter()).startswith("NumpyRandomSeedSetter(")
+
+
+@numpy_available
+def test_numpy_random_seed_setter_manual_seed() -> None:
+    seed_setter = NumpyRandomSeedSetter()
+    seed_setter.manual_seed(42)
+    x1 = np.random.randn(4, 6)
+    x2 = np.random.randn(4, 6)
+    seed_setter.manual_seed(42)
+    x3 = np.random.randn(4, 6)
+    assert np.array_equal(x1, x3)
+    assert not np.array_equal(x1, x2)
+
+
+def test_numpy_random_seed_setter_no_numpy() -> None:
+    with (
+        patch("coola.utils.imports.is_numpy_available", lambda: False),
+        pytest.raises(RuntimeError, match="`numpy` package is required but not installed."),
+    ):
+        NumpyRandomSeedSetter()