EnvironmentVarGuard, TESTFN, check_warnings, forget, is_jython,

make_legacy_pyc, rmtree, run_unittest, swap_attr, swap_item, temp_umask,

unlink, unload, create_empty_file, cpython_only, TESTFN_UNENCODABLE,

temp_dir)

temp_dir, DirsOnSysPath)

from test.support import script_helper

from test.test_importlib.util import uncache

skip_if_dont_write_bytecode = unittest.skipIf(

# Check relative import fails with only __package__ wrong

ns = dict(__package__='foo', __name__='test.notarealmodule')

self.assertRaises(SystemError, check_relative)

self.assertRaises(ModuleNotFoundError, check_relative)

# Check relative import fails with __package__ and __name__ wrong

ns = dict(__package__='foo', __name__='notarealpkg.notarealmodule')

self.assertRaises(SystemError, check_relative)

self.assertRaises(ModuleNotFoundError, check_relative)

# Check relative import fails with package set to a non-string

ns = dict(__package__=object())

self.fail("explicit relative import triggered an "

"implicit absolute import")

def test_import_from_non_package(self):

path = os.path.join(os.path.dirname(__file__), 'data', 'package2')

with uncache('submodule1', 'submodule2'), DirsOnSysPath(path):

with self.assertRaises(ImportError):

import submodule1

self.assertNotIn('submodule1', sys.modules)

self.assertNotIn('submodule2', sys.modules)

def test_import_from_unloaded_package(self):

with uncache('package2', 'package2.submodule1', 'package2.submodule2'), \

DirsOnSysPath(os.path.join(os.path.dirname(__file__), 'data')):

import package2.submodule1

package2.submodule1.submodule2

class OverridingImportBuiltinTests(unittest.TestCase):

def test_override_builtin(self):