2026-1-6

venv/Lib/site-packages/numpy/tests/test_lazyloading.py

@@ -0,0 +1,42 @@
+import subprocess
+import sys
+import textwrap
+
+import pytest
+
+from numpy.testing import IS_WASM
+
+
+@pytest.mark.skipif(IS_WASM, reason="can't start subprocess")
+def test_lazy_load():
+    # gh-22045. lazyload doesn't import submodule names into the namespace
+
+    # Test within a new process, to ensure that we do not mess with the
+    # global state during the test run (could lead to cryptic test failures).
+    # This is generally unsafe, especially, since we also reload the C-modules.
+    code = textwrap.dedent(r"""
+        import sys
+        from importlib.util import LazyLoader, find_spec, module_from_spec
+
+        # create lazy load of numpy as np
+        spec = find_spec("numpy")
+        module = module_from_spec(spec)
+        sys.modules["numpy"] = module
+        loader = LazyLoader(spec.loader)
+        loader.exec_module(module)
+        np = module
+
+        # test a subpackage import
+        from numpy.lib import recfunctions  # noqa: F401
+
+        # test triggering the import of the package
+        np.ndarray
+        """)
+    p = subprocess.run(
+        (sys.executable, '-c', code),
+        stdout=subprocess.PIPE,
+        stderr=subprocess.STDOUT,
+        encoding='utf-8',
+        check=False,
+    )
+    assert p.returncode == 0, p.stdout