cpython/Lib/test/test_site.py

"""Tests for 'site'.

Tests assume the initial paths in sys.path once the interpreter has begun
executing have not been removed.

"""
import unittest
import test.support
from test import support
from test.support.script_helper import assert_python_ok
from test.support import os_helper
from test.support import socket_helper
from test.support import captured_stderr
from test.support.os_helper import TESTFN, EnvironmentVarGuard
import ast
import builtins
import glob
import io
import os
import re
import shutil
import stat
import subprocess
import sys
import sysconfig
import tempfile
import urllib.error
import urllib.request
from unittest import mock
from copy import copy

# These tests are not particularly useful if Python was invoked with -S.
# If you add tests that are useful under -S, this skip should be moved
# to the class level.
if sys.flags.no_site:
    raise unittest.SkipTest("Python was invoked with -S")

import site


HAS_USER_SITE = (site.USER_SITE is not None)
OLD_SYS_PATH = None


def setUpModule():
    global OLD_SYS_PATH
    OLD_SYS_PATH = sys.path[:]

    if site.ENABLE_USER_SITE and not os.path.isdir(site.USER_SITE):
        # need to add user site directory for tests
        try:
            os.makedirs(site.USER_SITE)
            # modify sys.path: will be restored by tearDownModule()
            site.addsitedir(site.USER_SITE)
        except PermissionError as exc:
            raise unittest.SkipTest('unable to create user site directory (%r): %s'
                                    % (site.USER_SITE, exc))


def tearDownModule():
    sys.path[:] = OLD_SYS_PATH


class HelperFunctionsTests(unittest.TestCase):
    """Tests for helper functions.
    """

    def setUp(self):
        """Save a copy of sys.path"""
        self.sys_path = sys.path[:]
        self.old_base = site.USER_BASE
        self.old_site = site.USER_SITE
        self.old_prefixes = site.PREFIXES
        self.original_vars = sysconfig._CONFIG_VARS
        self.old_vars = copy(sysconfig._CONFIG_VARS)

    def tearDown(self):
        """Restore sys.path"""
        sys.path[:] = self.sys_path
        site.USER_BASE = self.old_base
        site.USER_SITE = self.old_site
        site.PREFIXES = self.old_prefixes
        sysconfig._CONFIG_VARS = self.original_vars
        # _CONFIG_VARS is None before get_config_vars() is called
        if sysconfig._CONFIG_VARS is not None:
            sysconfig._CONFIG_VARS.clear()
            sysconfig._CONFIG_VARS.update(self.old_vars)

    def test_makepath(self):
        # Test makepath() have an absolute path for its first return value
        # and a case-normalized version of the absolute path for its
        # second value.
        path_parts = ("Beginning", "End")
        original_dir = os.path.join(*path_parts)
        abs_dir, norm_dir = site.makepath(*path_parts)
        self.assertEqual(os.path.abspath(original_dir), abs_dir)
        if original_dir == os.path.normcase(original_dir):
            self.assertEqual(abs_dir, norm_dir)
        else:
            self.assertEqual(os.path.normcase(abs_dir), norm_dir)

    def test_init_pathinfo(self):
        dir_set = site._init_pathinfo()
        for entry in [site.makepath(path)[1] for path in sys.path
                        if path and os.path.exists(path)]:
            self.assertIn(entry, dir_set,
                          "%s from sys.path not found in set returned "
                          "by _init_pathinfo(): %s" % (entry, dir_set))

    def pth_file_tests(self, pth_file):
        """Contain common code for testing results of reading a .pth file"""
        self.assertIn(pth_file.imported, sys.modules,
                      "%s not in sys.modules" % pth_file.imported)
        self.assertIn(site.makepath(pth_file.good_dir_path)[0], sys.path)
        self.assertFalse(os.path.exists(pth_file.bad_dir_path))

    def test_addpackage(self):
        # Make sure addpackage() imports if the line starts with 'import',
        # adds directories to sys.path for any line in the file that is not a
        # comment or import that is a valid directory name for where the .pth
        # file resides; invalid directories are not added
        pth_file = PthFile()
        pth_file.cleanup(prep=True)  # to make sure that nothing is
                                      # pre-existing that shouldn't be
        try:
            pth_file.create()
            site.addpackage(pth_file.base_dir, pth_file.filename, set())
            self.pth_file_tests(pth_file)
        finally:
            pth_file.cleanup()

    def make_pth(self, contents, pth_dir='.', pth_name=TESTFN):
        # Create a .pth file and return its (abspath, basename).
        pth_dir = os.path.abspath(pth_dir)
        pth_basename = pth_name + '.pth'
        pth_fn = os.path.join(pth_dir, pth_basename)
        with open(pth_fn, 'w', encoding='utf-8') as pth_file:
            self.addCleanup(lambda: os.remove(pth_fn))
            pth_file.write(contents)
        return pth_dir, pth_basename

    def test_addpackage_import_bad_syntax(self):
        # Issue 10642
        pth_dir, pth_fn = self.make_pth("import bad-syntax\n")
        with captured_stderr() as err_out:
            site.addpackage(pth_dir, pth_fn, set())
        self.assertRegex(err_out.getvalue(), "line 1")
        self.assertRegex(err_out.getvalue(),
            re.escape(os.path.join(pth_dir, pth_fn)))
        # XXX: the previous two should be independent checks so that the
        # order doesn't matter.  The next three could be a single check
        # but my regex foo isn't good enough to write it.
        self.assertRegex(err_out.getvalue(), 'Traceback')
        self.assertRegex(err_out.getvalue(), r'import bad-syntax')
        self.assertRegex(err_out.getvalue(), 'SyntaxError')

    def test_addpackage_import_bad_exec(self):
        # Issue 10642
        pth_dir, pth_fn = self.make_pth("randompath\nimport nosuchmodule\n")
        with captured_stderr() as err_out:
            site.addpackage(pth_dir, pth_fn, set())
        self.assertRegex(err_out.getvalue(), "line 2")
        self.assertRegex(err_out.getvalue(),
            re.escape(os.path.join(pth_dir, pth_fn)))
        # XXX: ditto previous XXX comment.
        self.assertRegex(err_out.getvalue(), 'Traceback')
        self.assertRegex(err_out.getvalue(), 'ModuleNotFoundError')

    def test_addpackage_empty_lines(self):
        # Issue 33689
        pth_dir, pth_fn = self.make_pth("\n\n  \n\n")
        known_paths = site.addpackage(pth_dir, pth_fn, set())
        self.assertEqual(known_paths, set())

    def test_addpackage_import_bad_pth_file(self):
        # Issue 5258
        pth_dir, pth_fn = self.make_pth("abc\x00def\n")
        with captured_stderr() as err_out:
            self.assertFalse(site.addpackage(pth_dir, pth_fn, set()))
        self.maxDiff = None
        self.assertEqual(err_out.getvalue(), "")
        for path in sys.path:
            if isinstance(path, str):
                self.assertNotIn("abc\x00def", path)

    def test_addsitedir(self):
        # Same tests for test_addpackage since addsitedir() essentially just
        # calls addpackage() for every .pth file in the directory
        pth_file = PthFile()
        pth_file.cleanup(prep=True) # Make sure that nothing is pre-existing
                                    # that is tested for
        try:
            pth_file.create()
            site.addsitedir(pth_file.base_dir, set())
            self.pth_file_tests(pth_file)
        finally:
            pth_file.cleanup()

    def test_addsitedir_dotfile(self):
        pth_file = PthFile('.dotfile')
        pth_file.cleanup(prep=True)
        try:
            pth_file.create()
            site.addsitedir(pth_file.base_dir, set())
            self.assertNotIn(site.makepath(pth_file.good_dir_path)[0], sys.path)
            self.assertIn(pth_file.base_dir, sys.path)
        finally:
            pth_file.cleanup()

    @unittest.skipUnless(hasattr(os, 'chflags'), 'test needs os.chflags()')
    def test_addsitedir_hidden_flags(self):
        pth_file = PthFile()
        pth_file.cleanup(prep=True)
        try:
            pth_file.create()
            st = os.stat(pth_file.file_path)
            os.chflags(pth_file.file_path, st.st_flags | stat.UF_HIDDEN)
            site.addsitedir(pth_file.base_dir, set())
            self.assertNotIn(site.makepath(pth_file.good_dir_path)[0], sys.path)
            self.assertIn(pth_file.base_dir, sys.path)
        finally:
            pth_file.cleanup()

    @unittest.skipUnless(sys.platform == 'win32', 'test needs Windows')
    @support.requires_subprocess()
    def test_addsitedir_hidden_file_attribute(self):
        pth_file = PthFile()
        pth_file.cleanup(prep=True)
        try:
            pth_file.create()
            subprocess.check_call(['attrib', '+H', pth_file.file_path])
            site.addsitedir(pth_file.base_dir, set())
            self.assertNotIn(site.makepath(pth_file.good_dir_path)[0], sys.path)
            self.assertIn(pth_file.base_dir, sys.path)
        finally:
            pth_file.cleanup()

    # This tests _getuserbase, hence the double underline
    # to distinguish from a test for getuserbase
    def test__getuserbase(self):
        self.assertEqual(site._getuserbase(), sysconfig._getuserbase())

    @unittest.skipUnless(HAS_USER_SITE, 'need user site')
    def test_get_path(self):
        if sys.platform == 'darwin' and sys._framework:
            scheme = 'osx_framework_user'
        else:
            scheme = os.name + '_user'
        self.assertEqual(os.path.normpath(site._get_path(site._getuserbase())),
                         sysconfig.get_path('purelib', scheme))

    @unittest.skipUnless(site.ENABLE_USER_SITE, "requires access to PEP 370 "
                          "user-site (site.ENABLE_USER_SITE)")
    @support.requires_subprocess()
    def test_s_option(self):
        # (ncoghlan) Change this to use script_helper...
        usersite = os.path.normpath(site.USER_SITE)
        self.assertIn(usersite, sys.path)

        env = os.environ.copy()
        rc = subprocess.call([sys.executable, '-c',
            'import sys; sys.exit(%r in sys.path)' % usersite],
            env=env)
        self.assertEqual(rc, 1)

        env = os.environ.copy()
        rc = subprocess.call([sys.executable, '-s', '-c',
            'import sys; sys.exit(%r in sys.path)' % usersite],
            env=env)
        if usersite == site.getsitepackages()[0]:
            self.assertEqual(rc, 1)
        else:
            self.assertEqual(rc, 0, "User site still added to path with -s")

        env = os.environ.copy()
        env["PYTHONNOUSERSITE"] = "1"
        rc = subprocess.call([sys.executable, '-c',
            'import sys; sys.exit(%r in sys.path)' % usersite],
            env=env)
        if usersite == site.getsitepackages()[0]:
            self.assertEqual(rc, 1)
        else:
            self.assertEqual(rc, 0,
                        "User site still added to path with PYTHONNOUSERSITE")

        env = os.environ.copy()
        env["PYTHONUSERBASE"] = "/tmp"
        rc = subprocess.call([sys.executable, '-c',
            'import sys, site; sys.exit(site.USER_BASE.startswith("/tmp"))'],
            env=env)
        self.assertEqual(rc, 1,
                        "User base not set by PYTHONUSERBASE")

    @unittest.skipUnless(HAS_USER_SITE, 'need user site')
    def test_getuserbase(self):
        site.USER_BASE = None
        user_base = site.getuserbase()

        # the call sets site.USER_BASE
        self.assertEqual(site.USER_BASE, user_base)

        # let's set PYTHONUSERBASE and see if it uses it
        site.USER_BASE = None
        import sysconfig
        sysconfig._CONFIG_VARS = None

        with EnvironmentVarGuard() as environ:
            environ['PYTHONUSERBASE'] = 'xoxo'
            self.assertTrue(site.getuserbase().startswith('xoxo'),
                            site.getuserbase())

    @unittest.skipUnless(HAS_USER_SITE, 'need user site')
    def test_getusersitepackages(self):
        site.USER_SITE = None
        site.USER_BASE = None
        user_site = site.getusersitepackages()

        # the call sets USER_BASE *and* USER_SITE
        self.assertEqual(site.USER_SITE, user_site)
        self.assertTrue(user_site.startswith(site.USER_BASE), user_site)
        self.assertEqual(site.USER_BASE, site.getuserbase())

    def test_getsitepackages(self):
        site.PREFIXES = ['xoxo']
        dirs = site.getsitepackages()
        if os.sep == '/':
            # OS X, Linux, FreeBSD, etc
            if sys.platlibdir != "lib":
                self.assertEqual(len(dirs), 2)
                wanted = os.path.join('xoxo', sys.platlibdir,
                                      f'python{sysconfig._get_python_version_abi()}',
                                      'site-packages')
                self.assertEqual(dirs[0], wanted)
            else:
                self.assertEqual(len(dirs), 1)
            wanted = os.path.join('xoxo', 'lib',
                                  f'python{sysconfig._get_python_version_abi()}',
                                  'site-packages')
            self.assertEqual(dirs[-1], wanted)
        else:
            # other platforms
            self.assertEqual(len(dirs), 2)
            self.assertEqual(dirs[0], 'xoxo')
            wanted = os.path.join('xoxo', 'lib', 'site-packages')
            self.assertEqual(os.path.normcase(dirs[1]),
                             os.path.normcase(wanted))

    @unittest.skipUnless(HAS_USER_SITE, 'need user site')
    def test_no_home_directory(self):
        # bpo-10496: getuserbase() and getusersitepackages() must not fail if
        # the current user has no home directory (if expanduser() returns the
        # path unchanged).
        site.USER_SITE = None
        site.USER_BASE = None

        with EnvironmentVarGuard() as environ, \
             mock.patch('os.path.expanduser', lambda path: path):

            del environ['PYTHONUSERBASE']
            del environ['APPDATA']

            user_base = site.getuserbase()
            self.assertTrue(user_base.startswith('~' + os.sep),
                            user_base)

            user_site = site.getusersitepackages()
            self.assertTrue(user_site.startswith(user_base), user_site)

        with mock.patch('os.path.isdir', return_value=False) as mock_isdir, \
             mock.patch.object(site, 'addsitedir') as mock_addsitedir, \
             support.swap_attr(site, 'ENABLE_USER_SITE', True):

            # addusersitepackages() must not add user_site to sys.path
            # if it is not an existing directory
            known_paths = set()
            site.addusersitepackages(known_paths)

            mock_isdir.assert_called_once_with(user_site)
            mock_addsitedir.assert_not_called()
            self.assertFalse(known_paths)

    def test_gethistoryfile(self):
        filename = 'file'
        rc, out, err = assert_python_ok('-c',
            f'import site; assert site.gethistoryfile() == "{filename}"',
            PYTHON_HISTORY=filename)
        self.assertEqual(rc, 0)

        # Check that PYTHON_HISTORY is ignored in isolated mode.
        rc, out, err = assert_python_ok('-I', '-c',
            f'import site; assert site.gethistoryfile() != "{filename}"',
            PYTHON_HISTORY=filename)
        self.assertEqual(rc, 0)

    def test_trace(self):
        message = "bla-bla-bla"
        for verbose, out in (True, message + "\n"), (False, ""):
            with mock.patch('sys.flags', mock.Mock(verbose=verbose)), \
                    mock.patch('sys.stderr', io.StringIO()):
                site._trace(message)
                self.assertEqual(sys.stderr.getvalue(), out)


class PthFile(object):
    """Helper class for handling testing of .pth files"""

    def __init__(self, filename_base=TESTFN, imported="time",
                    good_dirname="__testdir__", bad_dirname="__bad"):
        """Initialize instance variables"""
        self.filename = filename_base + ".pth"
        self.base_dir = os.path.abspath('')
        self.file_path = os.path.join(self.base_dir, self.filename)
        self.imported = imported
        self.good_dirname = good_dirname
        self.bad_dirname = bad_dirname
        self.good_dir_path = os.path.join(self.base_dir, self.good_dirname)
        self.bad_dir_path = os.path.join(self.base_dir, self.bad_dirname)

    def create(self):
        """Create a .pth file with a comment, blank lines, an ``import
        <self.imported>``, a line with self.good_dirname, and a line with
        self.bad_dirname.

        Creation of the directory for self.good_dir_path (based off of
        self.good_dirname) is also performed.

        Make sure to call self.cleanup() to undo anything done by this method.

        """
        FILE = open(self.file_path, 'w')
        try:
            print("#import @bad module name", file=FILE)
            print("\n", file=FILE)
            print("import %s" % self.imported, file=FILE)
            print(self.good_dirname, file=FILE)
            print(self.bad_dirname, file=FILE)
        finally:
            FILE.close()
        os.mkdir(self.good_dir_path)

    def cleanup(self, prep=False):
        """Make sure that the .pth file is deleted, self.imported is not in
        sys.modules, and that both self.good_dirname and self.bad_dirname are
        not existing directories."""
        if os.path.exists(self.file_path):
            os.remove(self.file_path)
        if prep:
            self.imported_module = sys.modules.get(self.imported)
            if self.imported_module:
                del sys.modules[self.imported]
        else:
            if self.imported_module:
                sys.modules[self.imported] = self.imported_module
        if os.path.exists(self.good_dir_path):
            os.rmdir(self.good_dir_path)
        if os.path.exists(self.bad_dir_path):
            os.rmdir(self.bad_dir_path)

class ImportSideEffectTests(unittest.TestCase):
    """Test side-effects from importing 'site'."""

    def setUp(self):
        """Make a copy of sys.path"""
        self.sys_path = sys.path[:]

    def tearDown(self):
        """Restore sys.path"""
        sys.path[:] = self.sys_path

    def test_abs_paths_cached_None(self):
        """Test for __cached__ is None.

        Regarding to PEP 3147, __cached__ can be None.

        See also: https://bugs.python.org/issue30167
        """
        sys.modules['test'].__cached__ = None
        site.abs_paths()
        self.assertIsNone(sys.modules['test'].__cached__)

    def test_no_duplicate_paths(self):
        # No duplicate paths should exist in sys.path
        # Handled by removeduppaths()
        site.removeduppaths()
        seen_paths = set()
        for path in sys.path:
            self.assertNotIn(path, seen_paths)
            seen_paths.add(path)

    @unittest.skip('test not implemented')
    def test_add_build_dir(self):
        # Test that the build directory's Modules directory is used when it
        # should be.
        # XXX: implement
        pass

    def test_setting_quit(self):
        # 'quit' and 'exit' should be injected into builtins
        self.assertTrue(hasattr(builtins, "quit"))
        self.assertTrue(hasattr(builtins, "exit"))

    def test_setting_copyright(self):
        # 'copyright', 'credits', and 'license' should be in builtins
        self.assertTrue(hasattr(builtins, "copyright"))
        self.assertTrue(hasattr(builtins, "credits"))
        self.assertTrue(hasattr(builtins, "license"))

    def test_setting_help(self):
        # 'help' should be set in builtins
        self.assertTrue(hasattr(builtins, "help"))

    def test_sitecustomize_executed(self):
        # If sitecustomize is available, it should have been imported.
        if "sitecustomize" not in sys.modules:
            try:
                import sitecustomize  # noqa: F401
            except ImportError:
                pass
            else:
                self.fail("sitecustomize not imported automatically")

    @support.requires_subprocess()
    def test_customization_modules_on_startup(self):
        mod_names = [
            'sitecustomize'
        ]

        if site.ENABLE_USER_SITE:
            mod_names.append('usercustomize')

        temp_dir = tempfile.mkdtemp()
        self.addCleanup(os_helper.rmtree, temp_dir)

        with EnvironmentVarGuard() as environ:
            environ['PYTHONPATH'] = temp_dir

            for module_name in mod_names:
                os_helper.rmtree(temp_dir)
                os.mkdir(temp_dir)

                customize_path = os.path.join(temp_dir, f'{module_name}.py')
                eyecatcher = f'EXECUTED_{module_name}'

                with open(customize_path, 'w') as f:
                    f.write(f'print("{eyecatcher}")')

                output = subprocess.check_output([sys.executable, '-c', '""'])
                self.assertIn(eyecatcher, output.decode('utf-8'))

                # -S blocks any site-packages
                output = subprocess.check_output([sys.executable, '-S', '-c', '""'])
                self.assertNotIn(eyecatcher, output.decode('utf-8'))

                # -s blocks user site-packages
                if 'usercustomize' == module_name:
                    output = subprocess.check_output([sys.executable, '-s', '-c', '""'])
                    self.assertNotIn(eyecatcher, output.decode('utf-8'))


    @unittest.skipUnless(hasattr(urllib.request, "HTTPSHandler"),
                         'need SSL support to download license')
    @test.support.requires_resource('network')
    @test.support.system_must_validate_cert
    def test_license_exists_at_url(self):
        # This test is a bit fragile since it depends on the format of the
        # string displayed by license in the absence of a LICENSE file.
        url = license._Printer__data.split()[1]
        req = urllib.request.Request(url, method='HEAD')
        # Reset global urllib.request._opener
        self.addCleanup(urllib.request.urlcleanup)
        try:
            with socket_helper.transient_internet(url):
                with urllib.request.urlopen(req) as data:
                    code = data.getcode()
        except urllib.error.HTTPError as e:
            code = e.code
        self.assertEqual(code, 200, msg="Can't find " + url)


class StartupImportTests(unittest.TestCase):

    @support.requires_subprocess()
    def test_startup_imports(self):
        # Get sys.path in isolated mode (python3 -I)
        popen = subprocess.Popen([sys.executable, '-X', 'utf8', '-I',
                                  '-c', 'import sys; print(repr(sys.path))'],
                                 stdout=subprocess.PIPE,
                                 encoding='utf-8',
                                 errors='surrogateescape')
        stdout = popen.communicate()[0]
        self.assertEqual(popen.returncode, 0, repr(stdout))
        isolated_paths = ast.literal_eval(stdout)

        # bpo-27807: Even with -I, the site module executes all .pth files
        # found in sys.path (see site.addpackage()). Skip the test if at least
        # one .pth file is found.
        for path in isolated_paths:
            pth_files = glob.glob(os.path.join(glob.escape(path), "*.pth"))
            if pth_files:
                self.skipTest(f"found {len(pth_files)} .pth files in: {path}")

        # This tests checks which modules are loaded by Python when it
        # initially starts upon startup.
        popen = subprocess.Popen([sys.executable, '-X', 'utf8', '-I', '-v',
                                  '-c', 'import sys; print(set(sys.modules))'],
                                 stdout=subprocess.PIPE,
                                 stderr=subprocess.PIPE,
                                 encoding='utf-8',
                                 errors='surrogateescape')
        stdout, stderr = popen.communicate()
        self.assertEqual(popen.returncode, 0, (stdout, stderr))
        modules = ast.literal_eval(stdout)

        self.assertIn('site', modules)

        # http://bugs.python.org/issue19205
        re_mods = {'re', '_sre', 're._compiler', 're._constants', 're._parser'}
        self.assertFalse(modules.intersection(re_mods), stderr)

        # http://bugs.python.org/issue9548
        self.assertNotIn('locale', modules, stderr)

        # http://bugs.python.org/issue19209
        self.assertNotIn('copyreg', modules, stderr)

        # http://bugs.python.org/issue19218
        collection_mods = {'_collections', 'collections', 'functools',
                           'heapq', 'itertools', 'keyword', 'operator',
                           'reprlib', 'types', 'weakref'
                          }.difference(sys.builtin_module_names)
        self.assertFalse(modules.intersection(collection_mods), stderr)

    @support.requires_subprocess()
    def test_startup_interactivehook(self):
        r = subprocess.Popen([sys.executable, '-c',
            'import sys; sys.exit(hasattr(sys, "__interactivehook__"))']).wait()
        self.assertTrue(r, "'__interactivehook__' not added by site")

    @support.requires_subprocess()
    def test_startup_interactivehook_isolated(self):
        # issue28192 readline is not automatically enabled in isolated mode
        r = subprocess.Popen([sys.executable, '-I', '-c',
            'import sys; sys.exit(hasattr(sys, "__interactivehook__"))']).wait()
        self.assertFalse(r, "'__interactivehook__' added in isolated mode")

    @support.requires_subprocess()
    def test_startup_interactivehook_isolated_explicit(self):
        # issue28192 readline can be explicitly enabled in isolated mode
        r = subprocess.Popen([sys.executable, '-I', '-c',
            'import site, sys; site.enablerlcompleter(); sys.exit(hasattr(sys, "__interactivehook__"))']).wait()
        self.assertTrue(r, "'__interactivehook__' not added by enablerlcompleter()")

class _pthFileTests(unittest.TestCase):

    if sys.platform == 'win32':
        def _create_underpth_exe(self, lines, exe_pth=True):
            import _winapi
            temp_dir = tempfile.mkdtemp()
            self.addCleanup(os_helper.rmtree, temp_dir)
            exe_file = os.path.join(temp_dir, os.path.split(sys.executable)[1])
            dll_src_file = _winapi.GetModuleFileName(sys.dllhandle)
            dll_file = os.path.join(temp_dir, os.path.split(dll_src_file)[1])
            shutil.copy(sys.executable, exe_file)
            shutil.copy(dll_src_file, dll_file)
            for fn in glob.glob(os.path.join(os.path.split(dll_src_file)[0], "vcruntime*.dll")):
                shutil.copy(fn, os.path.join(temp_dir, os.path.split(fn)[1]))
            if exe_pth:
                _pth_file = os.path.splitext(exe_file)[0] + '._pth'
            else:
                _pth_file = os.path.splitext(dll_file)[0] + '._pth'
            with open(_pth_file, 'w', encoding='utf8') as f:
                for line in lines:
                    print(line, file=f)
            return exe_file
    else:
        def _create_underpth_exe(self, lines, exe_pth=True):
            if not exe_pth:
                raise unittest.SkipTest("library ._pth file not supported on this platform")
            temp_dir = tempfile.mkdtemp()
            self.addCleanup(os_helper.rmtree, temp_dir)
            exe_file = os.path.join(temp_dir, os.path.split(sys.executable)[1])
            os.symlink(sys.executable, exe_file)
            _pth_file = exe_file + '._pth'
            with open(_pth_file, 'w') as f:
                for line in lines:
                    print(line, file=f)
            return exe_file

    def _calc_sys_path_for_underpth_nosite(self, sys_prefix, lines):
        sys_path = []
        for line in lines:
            if not line or line[0] == '#':
                continue
            abs_path = os.path.abspath(os.path.join(sys_prefix, line))
            sys_path.append(abs_path)
        return sys_path

    def _get_pth_lines(self, libpath: str, *, import_site: bool):
        pth_lines = ['fake-path-name']
        # include 200 lines of `libpath` in _pth lines (or fewer
        # if the `libpath` is long enough to get close to 32KB
        # see https://github.com/python/cpython/issues/113628)
        encoded_libpath_length = len(libpath.encode("utf-8"))
        repetitions = min(200, 30000 // encoded_libpath_length)
        if repetitions <= 2:
            self.skipTest(
                f"Python stdlib path is too long ({encoded_libpath_length:,} bytes)")
        pth_lines.extend(libpath for _ in range(repetitions))
        pth_lines.extend(['', '# comment'])
        if import_site:
            pth_lines.append('import site')
        return pth_lines

    @support.requires_subprocess()
    def test_underpth_basic(self):
        pth_lines = ['#.', '# ..', *sys.path, '.', '..']
        exe_file = self._create_underpth_exe(pth_lines)
        sys_path = self._calc_sys_path_for_underpth_nosite(
            os.path.dirname(exe_file),
            pth_lines)

        output = subprocess.check_output([exe_file, '-X', 'utf8', '-c',
            'import sys; print("\\n".join(sys.path) if sys.flags.no_site else "")'
        ], encoding='utf-8', errors='surrogateescape')
        actual_sys_path = output.rstrip().split('\n')
        self.assertTrue(actual_sys_path, "sys.flags.no_site was False")
        self.assertEqual(
            actual_sys_path,
            sys_path,
            "sys.path is incorrect"
        )

    @support.requires_subprocess()
    def test_underpth_nosite_file(self):
        libpath = test.support.STDLIB_DIR
        exe_prefix = os.path.dirname(sys.executable)
        pth_lines = self._get_pth_lines(libpath, import_site=False)
        exe_file = self._create_underpth_exe(pth_lines)
        sys_path = self._calc_sys_path_for_underpth_nosite(
            os.path.dirname(exe_file),
            pth_lines)

        env = os.environ.copy()
        env['PYTHONPATH'] = 'from-env'
        env['PATH'] = '{}{}{}'.format(exe_prefix, os.pathsep, os.getenv('PATH'))
        output = subprocess.check_output([exe_file, '-c',
            'import sys; print("\\n".join(sys.path) if sys.flags.no_site else "")'
        ], env=env, encoding='utf-8', errors='surrogateescape')
        actual_sys_path = output.rstrip().split('\n')
        self.assertTrue(actual_sys_path, "sys.flags.no_site was False")
        self.assertEqual(
            actual_sys_path,
            sys_path,
            "sys.path is incorrect"
        )

    @support.requires_subprocess()
    def test_underpth_file(self):
        libpath = test.support.STDLIB_DIR
        exe_prefix = os.path.dirname(sys.executable)
        exe_file = self._create_underpth_exe(
            self._get_pth_lines(libpath, import_site=True))
        sys_prefix = os.path.dirname(exe_file)
        env = os.environ.copy()
        env['PYTHONPATH'] = 'from-env'
        env['PATH'] = '{};{}'.format(exe_prefix, os.getenv('PATH'))
        rc = subprocess.call([exe_file, '-c',
            'import sys; sys.exit(not sys.flags.no_site and '
            '%r in sys.path and %r in sys.path and %r not in sys.path and '
            'all("\\r" not in p and "\\n" not in p for p in sys.path))' % (
                os.path.join(sys_prefix, 'fake-path-name'),
                libpath,
                os.path.join(sys_prefix, 'from-env'),
            )], env=env)
        self.assertTrue(rc, "sys.path is incorrect")

    @support.requires_subprocess()
    def test_underpth_dll_file(self):
        libpath = test.support.STDLIB_DIR
        exe_prefix = os.path.dirname(sys.executable)
        exe_file = self._create_underpth_exe(
            self._get_pth_lines(libpath, import_site=True), exe_pth=False)
        sys_prefix = os.path.dirname(exe_file)
        env = os.environ.copy()
        env['PYTHONPATH'] = 'from-env'
        env['PATH'] = '{};{}'.format(exe_prefix, os.getenv('PATH'))
        rc = subprocess.call([exe_file, '-c',
            'import sys; sys.exit(not sys.flags.no_site and '
            '%r in sys.path and %r in sys.path and %r not in sys.path and '
            'all("\\r" not in p and "\\n" not in p for p in sys.path))' % (
                os.path.join(sys_prefix, 'fake-path-name'),
                libpath,
                os.path.join(sys_prefix, 'from-env'),
            )], env=env)
        self.assertTrue(rc, "sys.path is incorrect")


if __name__ == "__main__":
    unittest.main()