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