demonstrate that `python -O` removes `assert`

assert_test.py

# test assert vs assert_
# run with
#      python assert_test.py
# and
#      python -O assert_test.py
#
# to see that assert is optimized away by -O

from numpy.testing import assert_

def test_py_assert():
    assert 1 == 2, "assert found an error"

def test_np_assert():
    assert_(1 == 2, "assert_ found an error")

if __name__ == "__main__":
    try:
        test_py_assert()
    except AssertionError as err:
        print(err)
    else:
        print("py_assert did not raise exception but it should have!")

    try:
        test_np_assert()
    except AssertionError as err:
        print(err)
    else:
        print("np_assert did not raise exception but it should have!")