cpython/Lib/test/test_sys.py
Mark Shannon cb9879b948
bpo-40941: Unify implicit and explicit state in the frame and generator objects into a single value. (GH-20803)
* Merge gen and frame state variables into one.

* Replace stack pointer with depth in PyFrameObject. Makes code easier to read and saves a word of memory.
2020-07-17 11:44:23 +01:00

1476 lines
56 KiB
Python

import builtins
import codecs
import gc
import locale
import operator
import os
import struct
import subprocess
import sys
import sysconfig
import test.support
from test import support
from test.support.script_helper import assert_python_ok, assert_python_failure
from test.support import threading_helper
import textwrap
import unittest
import warnings
# count the number of test runs, used to create unique
# strings to intern in test_intern()
INTERN_NUMRUNS = 0
class DisplayHookTest(unittest.TestCase):
def test_original_displayhook(self):
dh = sys.__displayhook__
with support.captured_stdout() as out:
dh(42)
self.assertEqual(out.getvalue(), "42\n")
self.assertEqual(builtins._, 42)
del builtins._
with support.captured_stdout() as out:
dh(None)
self.assertEqual(out.getvalue(), "")
self.assertTrue(not hasattr(builtins, "_"))
# sys.displayhook() requires arguments
self.assertRaises(TypeError, dh)
stdout = sys.stdout
try:
del sys.stdout
self.assertRaises(RuntimeError, dh, 42)
finally:
sys.stdout = stdout
def test_lost_displayhook(self):
displayhook = sys.displayhook
try:
del sys.displayhook
code = compile("42", "<string>", "single")
self.assertRaises(RuntimeError, eval, code)
finally:
sys.displayhook = displayhook
def test_custom_displayhook(self):
def baddisplayhook(obj):
raise ValueError
with support.swap_attr(sys, 'displayhook', baddisplayhook):
code = compile("42", "<string>", "single")
self.assertRaises(ValueError, eval, code)
class ExceptHookTest(unittest.TestCase):
def test_original_excepthook(self):
try:
raise ValueError(42)
except ValueError as exc:
with support.captured_stderr() as err:
sys.__excepthook__(*sys.exc_info())
self.assertTrue(err.getvalue().endswith("ValueError: 42\n"))
self.assertRaises(TypeError, sys.__excepthook__)
def test_excepthook_bytes_filename(self):
# bpo-37467: sys.excepthook() must not crash if a filename
# is a bytes string
with warnings.catch_warnings():
warnings.simplefilter('ignore', BytesWarning)
try:
raise SyntaxError("msg", (b"bytes_filename", 123, 0, "text"))
except SyntaxError as exc:
with support.captured_stderr() as err:
sys.__excepthook__(*sys.exc_info())
err = err.getvalue()
self.assertIn(""" File "b'bytes_filename'", line 123\n""", err)
self.assertIn(""" text\n""", err)
self.assertTrue(err.endswith("SyntaxError: msg\n"))
def test_excepthook(self):
with test.support.captured_output("stderr") as stderr:
sys.excepthook(1, '1', 1)
self.assertTrue("TypeError: print_exception(): Exception expected for " \
"value, str found" in stderr.getvalue())
# FIXME: testing the code for a lost or replaced excepthook in
# Python/pythonrun.c::PyErr_PrintEx() is tricky.
class SysModuleTest(unittest.TestCase):
def tearDown(self):
test.support.reap_children()
def test_exit(self):
# call with two arguments
self.assertRaises(TypeError, sys.exit, 42, 42)
# call without argument
with self.assertRaises(SystemExit) as cm:
sys.exit()
self.assertIsNone(cm.exception.code)
rc, out, err = assert_python_ok('-c', 'import sys; sys.exit()')
self.assertEqual(rc, 0)
self.assertEqual(out, b'')
self.assertEqual(err, b'')
# call with integer argument
with self.assertRaises(SystemExit) as cm:
sys.exit(42)
self.assertEqual(cm.exception.code, 42)
# call with tuple argument with one entry
# entry will be unpacked
with self.assertRaises(SystemExit) as cm:
sys.exit((42,))
self.assertEqual(cm.exception.code, 42)
# call with string argument
with self.assertRaises(SystemExit) as cm:
sys.exit("exit")
self.assertEqual(cm.exception.code, "exit")
# call with tuple argument with two entries
with self.assertRaises(SystemExit) as cm:
sys.exit((17, 23))
self.assertEqual(cm.exception.code, (17, 23))
# test that the exit machinery handles SystemExits properly
rc, out, err = assert_python_failure('-c', 'raise SystemExit(47)')
self.assertEqual(rc, 47)
self.assertEqual(out, b'')
self.assertEqual(err, b'')
def check_exit_message(code, expected, **env_vars):
rc, out, err = assert_python_failure('-c', code, **env_vars)
self.assertEqual(rc, 1)
self.assertEqual(out, b'')
self.assertTrue(err.startswith(expected),
"%s doesn't start with %s" % (ascii(err), ascii(expected)))
# test that stderr buffer is flushed before the exit message is written
# into stderr
check_exit_message(
r'import sys; sys.stderr.write("unflushed,"); sys.exit("message")',
b"unflushed,message")
# test that the exit message is written with backslashreplace error
# handler to stderr
check_exit_message(
r'import sys; sys.exit("surrogates:\uDCFF")',
b"surrogates:\\udcff")
# test that the unicode message is encoded to the stderr encoding
# instead of the default encoding (utf8)
check_exit_message(
r'import sys; sys.exit("h\xe9")',
b"h\xe9", PYTHONIOENCODING='latin-1')
def test_getdefaultencoding(self):
self.assertRaises(TypeError, sys.getdefaultencoding, 42)
# can't check more than the type, as the user might have changed it
self.assertIsInstance(sys.getdefaultencoding(), str)
# testing sys.settrace() is done in test_sys_settrace.py
# testing sys.setprofile() is done in test_sys_setprofile.py
def test_switchinterval(self):
self.assertRaises(TypeError, sys.setswitchinterval)
self.assertRaises(TypeError, sys.setswitchinterval, "a")
self.assertRaises(ValueError, sys.setswitchinterval, -1.0)
self.assertRaises(ValueError, sys.setswitchinterval, 0.0)
orig = sys.getswitchinterval()
# sanity check
self.assertTrue(orig < 0.5, orig)
try:
for n in 0.00001, 0.05, 3.0, orig:
sys.setswitchinterval(n)
self.assertAlmostEqual(sys.getswitchinterval(), n)
finally:
sys.setswitchinterval(orig)
def test_recursionlimit(self):
self.assertRaises(TypeError, sys.getrecursionlimit, 42)
oldlimit = sys.getrecursionlimit()
self.assertRaises(TypeError, sys.setrecursionlimit)
self.assertRaises(ValueError, sys.setrecursionlimit, -42)
sys.setrecursionlimit(10000)
self.assertEqual(sys.getrecursionlimit(), 10000)
sys.setrecursionlimit(oldlimit)
def test_recursionlimit_recovery(self):
if hasattr(sys, 'gettrace') and sys.gettrace():
self.skipTest('fatal error if run with a trace function')
oldlimit = sys.getrecursionlimit()
def f():
f()
try:
for depth in (10, 25, 50, 75, 100, 250, 1000):
try:
sys.setrecursionlimit(depth)
except RecursionError:
# Issue #25274: The recursion limit is too low at the
# current recursion depth
continue
# Issue #5392: test stack overflow after hitting recursion
# limit twice
self.assertRaises(RecursionError, f)
self.assertRaises(RecursionError, f)
finally:
sys.setrecursionlimit(oldlimit)
@test.support.cpython_only
def test_setrecursionlimit_recursion_depth(self):
# Issue #25274: Setting a low recursion limit must be blocked if the
# current recursion depth is already higher than the "lower-water
# mark". Otherwise, it may not be possible anymore to
# reset the overflowed flag to 0.
from _testinternalcapi import get_recursion_depth
def set_recursion_limit_at_depth(depth, limit):
recursion_depth = get_recursion_depth()
if recursion_depth >= depth:
with self.assertRaises(RecursionError) as cm:
sys.setrecursionlimit(limit)
self.assertRegex(str(cm.exception),
"cannot set the recursion limit to [0-9]+ "
"at the recursion depth [0-9]+: "
"the limit is too low")
else:
set_recursion_limit_at_depth(depth, limit)
oldlimit = sys.getrecursionlimit()
try:
sys.setrecursionlimit(1000)
for limit in (10, 25, 50, 75, 100, 150, 200):
# formula extracted from _Py_RecursionLimitLowerWaterMark()
if limit > 200:
depth = limit - 50
else:
depth = limit * 3 // 4
set_recursion_limit_at_depth(depth, limit)
finally:
sys.setrecursionlimit(oldlimit)
# The error message is specific to CPython
@test.support.cpython_only
def test_recursionlimit_fatalerror(self):
# A fatal error occurs if a second recursion limit is hit when recovering
# from a first one.
code = textwrap.dedent("""
import sys
def f():
try:
f()
except RecursionError:
f()
sys.setrecursionlimit(%d)
f()""")
with test.support.SuppressCrashReport():
for i in (50, 1000):
sub = subprocess.Popen([sys.executable, '-c', code % i],
stderr=subprocess.PIPE)
err = sub.communicate()[1]
self.assertTrue(sub.returncode, sub.returncode)
self.assertIn(
b"Fatal Python error: _Py_CheckRecursiveCall: "
b"Cannot recover from stack overflow",
err)
def test_getwindowsversion(self):
# Raise SkipTest if sys doesn't have getwindowsversion attribute
test.support.get_attribute(sys, "getwindowsversion")
v = sys.getwindowsversion()
self.assertEqual(len(v), 5)
self.assertIsInstance(v[0], int)
self.assertIsInstance(v[1], int)
self.assertIsInstance(v[2], int)
self.assertIsInstance(v[3], int)
self.assertIsInstance(v[4], str)
self.assertRaises(IndexError, operator.getitem, v, 5)
self.assertIsInstance(v.major, int)
self.assertIsInstance(v.minor, int)
self.assertIsInstance(v.build, int)
self.assertIsInstance(v.platform, int)
self.assertIsInstance(v.service_pack, str)
self.assertIsInstance(v.service_pack_minor, int)
self.assertIsInstance(v.service_pack_major, int)
self.assertIsInstance(v.suite_mask, int)
self.assertIsInstance(v.product_type, int)
self.assertEqual(v[0], v.major)
self.assertEqual(v[1], v.minor)
self.assertEqual(v[2], v.build)
self.assertEqual(v[3], v.platform)
self.assertEqual(v[4], v.service_pack)
# This is how platform.py calls it. Make sure tuple
# still has 5 elements
maj, min, buildno, plat, csd = sys.getwindowsversion()
def test_call_tracing(self):
self.assertRaises(TypeError, sys.call_tracing, type, 2)
@unittest.skipUnless(hasattr(sys, "setdlopenflags"),
'test needs sys.setdlopenflags()')
def test_dlopenflags(self):
self.assertTrue(hasattr(sys, "getdlopenflags"))
self.assertRaises(TypeError, sys.getdlopenflags, 42)
oldflags = sys.getdlopenflags()
self.assertRaises(TypeError, sys.setdlopenflags)
sys.setdlopenflags(oldflags+1)
self.assertEqual(sys.getdlopenflags(), oldflags+1)
sys.setdlopenflags(oldflags)
@test.support.refcount_test
def test_refcount(self):
# n here must be a global in order for this test to pass while
# tracing with a python function. Tracing calls PyFrame_FastToLocals
# which will add a copy of any locals to the frame object, causing
# the reference count to increase by 2 instead of 1.
global n
self.assertRaises(TypeError, sys.getrefcount)
c = sys.getrefcount(None)
n = None
self.assertEqual(sys.getrefcount(None), c+1)
del n
self.assertEqual(sys.getrefcount(None), c)
if hasattr(sys, "gettotalrefcount"):
self.assertIsInstance(sys.gettotalrefcount(), int)
def test_getframe(self):
self.assertRaises(TypeError, sys._getframe, 42, 42)
self.assertRaises(ValueError, sys._getframe, 2000000000)
self.assertTrue(
SysModuleTest.test_getframe.__code__ \
is sys._getframe().f_code
)
# sys._current_frames() is a CPython-only gimmick.
@threading_helper.reap_threads
def test_current_frames(self):
import threading
import traceback
# Spawn a thread that blocks at a known place. Then the main
# thread does sys._current_frames(), and verifies that the frames
# returned make sense.
entered_g = threading.Event()
leave_g = threading.Event()
thread_info = [] # the thread's id
def f123():
g456()
def g456():
thread_info.append(threading.get_ident())
entered_g.set()
leave_g.wait()
t = threading.Thread(target=f123)
t.start()
entered_g.wait()
# At this point, t has finished its entered_g.set(), although it's
# impossible to guess whether it's still on that line or has moved on
# to its leave_g.wait().
self.assertEqual(len(thread_info), 1)
thread_id = thread_info[0]
d = sys._current_frames()
for tid in d:
self.assertIsInstance(tid, int)
self.assertGreater(tid, 0)
main_id = threading.get_ident()
self.assertIn(main_id, d)
self.assertIn(thread_id, d)
# Verify that the captured main-thread frame is _this_ frame.
frame = d.pop(main_id)
self.assertTrue(frame is sys._getframe())
# Verify that the captured thread frame is blocked in g456, called
# from f123. This is a litte tricky, since various bits of
# threading.py are also in the thread's call stack.
frame = d.pop(thread_id)
stack = traceback.extract_stack(frame)
for i, (filename, lineno, funcname, sourceline) in enumerate(stack):
if funcname == "f123":
break
else:
self.fail("didn't find f123() on thread's call stack")
self.assertEqual(sourceline, "g456()")
# And the next record must be for g456().
filename, lineno, funcname, sourceline = stack[i+1]
self.assertEqual(funcname, "g456")
self.assertIn(sourceline, ["leave_g.wait()", "entered_g.set()"])
# Reap the spawned thread.
leave_g.set()
t.join()
def test_attributes(self):
self.assertIsInstance(sys.api_version, int)
self.assertIsInstance(sys.argv, list)
for arg in sys.argv:
self.assertIsInstance(arg, str)
self.assertIsInstance(sys.orig_argv, list)
for arg in sys.orig_argv:
self.assertIsInstance(arg, str)
self.assertIn(sys.byteorder, ("little", "big"))
self.assertIsInstance(sys.builtin_module_names, tuple)
self.assertIsInstance(sys.copyright, str)
self.assertIsInstance(sys.exec_prefix, str)
self.assertIsInstance(sys.base_exec_prefix, str)
self.assertIsInstance(sys.executable, str)
self.assertEqual(len(sys.float_info), 11)
self.assertEqual(sys.float_info.radix, 2)
self.assertEqual(len(sys.int_info), 2)
self.assertTrue(sys.int_info.bits_per_digit % 5 == 0)
self.assertTrue(sys.int_info.sizeof_digit >= 1)
self.assertEqual(type(sys.int_info.bits_per_digit), int)
self.assertEqual(type(sys.int_info.sizeof_digit), int)
self.assertIsInstance(sys.hexversion, int)
self.assertEqual(len(sys.hash_info), 9)
self.assertLess(sys.hash_info.modulus, 2**sys.hash_info.width)
# sys.hash_info.modulus should be a prime; we do a quick
# probable primality test (doesn't exclude the possibility of
# a Carmichael number)
for x in range(1, 100):
self.assertEqual(
pow(x, sys.hash_info.modulus-1, sys.hash_info.modulus),
1,
"sys.hash_info.modulus {} is a non-prime".format(
sys.hash_info.modulus)
)
self.assertIsInstance(sys.hash_info.inf, int)
self.assertIsInstance(sys.hash_info.nan, int)
self.assertIsInstance(sys.hash_info.imag, int)
algo = sysconfig.get_config_var("Py_HASH_ALGORITHM")
if sys.hash_info.algorithm in {"fnv", "siphash24"}:
self.assertIn(sys.hash_info.hash_bits, {32, 64})
self.assertIn(sys.hash_info.seed_bits, {32, 64, 128})
if algo == 1:
self.assertEqual(sys.hash_info.algorithm, "siphash24")
elif algo == 2:
self.assertEqual(sys.hash_info.algorithm, "fnv")
else:
self.assertIn(sys.hash_info.algorithm, {"fnv", "siphash24"})
else:
# PY_HASH_EXTERNAL
self.assertEqual(algo, 0)
self.assertGreaterEqual(sys.hash_info.cutoff, 0)
self.assertLess(sys.hash_info.cutoff, 8)
self.assertIsInstance(sys.maxsize, int)
self.assertIsInstance(sys.maxunicode, int)
self.assertEqual(sys.maxunicode, 0x10FFFF)
self.assertIsInstance(sys.platform, str)
self.assertIsInstance(sys.prefix, str)
self.assertIsInstance(sys.base_prefix, str)
self.assertIsInstance(sys.platlibdir, str)
self.assertIsInstance(sys.version, str)
vi = sys.version_info
self.assertIsInstance(vi[:], tuple)
self.assertEqual(len(vi), 5)
self.assertIsInstance(vi[0], int)
self.assertIsInstance(vi[1], int)
self.assertIsInstance(vi[2], int)
self.assertIn(vi[3], ("alpha", "beta", "candidate", "final"))
self.assertIsInstance(vi[4], int)
self.assertIsInstance(vi.major, int)
self.assertIsInstance(vi.minor, int)
self.assertIsInstance(vi.micro, int)
self.assertIn(vi.releaselevel, ("alpha", "beta", "candidate", "final"))
self.assertIsInstance(vi.serial, int)
self.assertEqual(vi[0], vi.major)
self.assertEqual(vi[1], vi.minor)
self.assertEqual(vi[2], vi.micro)
self.assertEqual(vi[3], vi.releaselevel)
self.assertEqual(vi[4], vi.serial)
self.assertTrue(vi > (1,0,0))
self.assertIsInstance(sys.float_repr_style, str)
self.assertIn(sys.float_repr_style, ('short', 'legacy'))
if not sys.platform.startswith('win'):
self.assertIsInstance(sys.abiflags, str)
def test_thread_info(self):
info = sys.thread_info
self.assertEqual(len(info), 3)
self.assertIn(info.name, ('nt', 'pthread', 'solaris', None))
self.assertIn(info.lock, ('semaphore', 'mutex+cond', None))
def test_43581(self):
# Can't use sys.stdout, as this is a StringIO object when
# the test runs under regrtest.
self.assertEqual(sys.__stdout__.encoding, sys.__stderr__.encoding)
def test_intern(self):
global INTERN_NUMRUNS
INTERN_NUMRUNS += 1
self.assertRaises(TypeError, sys.intern)
s = "never interned before" + str(INTERN_NUMRUNS)
self.assertTrue(sys.intern(s) is s)
s2 = s.swapcase().swapcase()
self.assertTrue(sys.intern(s2) is s)
# Subclasses of string can't be interned, because they
# provide too much opportunity for insane things to happen.
# We don't want them in the interned dict and if they aren't
# actually interned, we don't want to create the appearance
# that they are by allowing intern() to succeed.
class S(str):
def __hash__(self):
return 123
self.assertRaises(TypeError, sys.intern, S("abc"))
def test_sys_flags(self):
self.assertTrue(sys.flags)
attrs = ("debug",
"inspect", "interactive", "optimize",
"dont_write_bytecode", "no_user_site", "no_site",
"ignore_environment", "verbose", "bytes_warning", "quiet",
"hash_randomization", "isolated", "dev_mode", "utf8_mode")
for attr in attrs:
self.assertTrue(hasattr(sys.flags, attr), attr)
attr_type = bool if attr == "dev_mode" else int
self.assertEqual(type(getattr(sys.flags, attr)), attr_type, attr)
self.assertTrue(repr(sys.flags))
self.assertEqual(len(sys.flags), len(attrs))
self.assertIn(sys.flags.utf8_mode, {0, 1, 2})
def assert_raise_on_new_sys_type(self, sys_attr):
# Users are intentionally prevented from creating new instances of
# sys.flags, sys.version_info, and sys.getwindowsversion.
attr_type = type(sys_attr)
with self.assertRaises(TypeError):
attr_type()
with self.assertRaises(TypeError):
attr_type.__new__(attr_type)
def test_sys_flags_no_instantiation(self):
self.assert_raise_on_new_sys_type(sys.flags)
def test_sys_version_info_no_instantiation(self):
self.assert_raise_on_new_sys_type(sys.version_info)
def test_sys_getwindowsversion_no_instantiation(self):
# Skip if not being run on Windows.
test.support.get_attribute(sys, "getwindowsversion")
self.assert_raise_on_new_sys_type(sys.getwindowsversion())
@test.support.cpython_only
def test_clear_type_cache(self):
sys._clear_type_cache()
def test_ioencoding(self):
env = dict(os.environ)
# Test character: cent sign, encoded as 0x4A (ASCII J) in CP424,
# not representable in ASCII.
env["PYTHONIOENCODING"] = "cp424"
p = subprocess.Popen([sys.executable, "-c", 'print(chr(0xa2))'],
stdout = subprocess.PIPE, env=env)
out = p.communicate()[0].strip()
expected = ("\xa2" + os.linesep).encode("cp424")
self.assertEqual(out, expected)
env["PYTHONIOENCODING"] = "ascii:replace"
p = subprocess.Popen([sys.executable, "-c", 'print(chr(0xa2))'],
stdout = subprocess.PIPE, env=env)
out = p.communicate()[0].strip()
self.assertEqual(out, b'?')
env["PYTHONIOENCODING"] = "ascii"
p = subprocess.Popen([sys.executable, "-c", 'print(chr(0xa2))'],
stdout=subprocess.PIPE, stderr=subprocess.PIPE,
env=env)
out, err = p.communicate()
self.assertEqual(out, b'')
self.assertIn(b'UnicodeEncodeError:', err)
self.assertIn(rb"'\xa2'", err)
env["PYTHONIOENCODING"] = "ascii:"
p = subprocess.Popen([sys.executable, "-c", 'print(chr(0xa2))'],
stdout=subprocess.PIPE, stderr=subprocess.PIPE,
env=env)
out, err = p.communicate()
self.assertEqual(out, b'')
self.assertIn(b'UnicodeEncodeError:', err)
self.assertIn(rb"'\xa2'", err)
env["PYTHONIOENCODING"] = ":surrogateescape"
p = subprocess.Popen([sys.executable, "-c", 'print(chr(0xdcbd))'],
stdout=subprocess.PIPE, env=env)
out = p.communicate()[0].strip()
self.assertEqual(out, b'\xbd')
@unittest.skipUnless(test.support.FS_NONASCII,
'requires OS support of non-ASCII encodings')
@unittest.skipUnless(sys.getfilesystemencoding() == locale.getpreferredencoding(False),
'requires FS encoding to match locale')
def test_ioencoding_nonascii(self):
env = dict(os.environ)
env["PYTHONIOENCODING"] = ""
p = subprocess.Popen([sys.executable, "-c",
'print(%a)' % test.support.FS_NONASCII],
stdout=subprocess.PIPE, env=env)
out = p.communicate()[0].strip()
self.assertEqual(out, os.fsencode(test.support.FS_NONASCII))
@unittest.skipIf(sys.base_prefix != sys.prefix,
'Test is not venv-compatible')
def test_executable(self):
# sys.executable should be absolute
self.assertEqual(os.path.abspath(sys.executable), sys.executable)
# Issue #7774: Ensure that sys.executable is an empty string if argv[0]
# has been set to a non existent program name and Python is unable to
# retrieve the real program name
# For a normal installation, it should work without 'cwd'
# argument. For test runs in the build directory, see #7774.
python_dir = os.path.dirname(os.path.realpath(sys.executable))
p = subprocess.Popen(
["nonexistent", "-c",
'import sys; print(sys.executable.encode("ascii", "backslashreplace"))'],
executable=sys.executable, stdout=subprocess.PIPE, cwd=python_dir)
stdout = p.communicate()[0]
executable = stdout.strip().decode("ASCII")
p.wait()
self.assertIn(executable, ["b''", repr(sys.executable.encode("ascii", "backslashreplace"))])
def check_fsencoding(self, fs_encoding, expected=None):
self.assertIsNotNone(fs_encoding)
codecs.lookup(fs_encoding)
if expected:
self.assertEqual(fs_encoding, expected)
def test_getfilesystemencoding(self):
fs_encoding = sys.getfilesystemencoding()
if sys.platform == 'darwin':
expected = 'utf-8'
else:
expected = None
self.check_fsencoding(fs_encoding, expected)
def c_locale_get_error_handler(self, locale, isolated=False, encoding=None):
# Force the POSIX locale
env = os.environ.copy()
env["LC_ALL"] = locale
env["PYTHONCOERCECLOCALE"] = "0"
code = '\n'.join((
'import sys',
'def dump(name):',
' std = getattr(sys, name)',
' print("%s: %s" % (name, std.errors))',
'dump("stdin")',
'dump("stdout")',
'dump("stderr")',
))
args = [sys.executable, "-X", "utf8=0", "-c", code]
if isolated:
args.append("-I")
if encoding is not None:
env['PYTHONIOENCODING'] = encoding
else:
env.pop('PYTHONIOENCODING', None)
p = subprocess.Popen(args,
stdout=subprocess.PIPE,
stderr=subprocess.STDOUT,
env=env,
universal_newlines=True)
stdout, stderr = p.communicate()
return stdout
def check_locale_surrogateescape(self, locale):
out = self.c_locale_get_error_handler(locale, isolated=True)
self.assertEqual(out,
'stdin: surrogateescape\n'
'stdout: surrogateescape\n'
'stderr: backslashreplace\n')
# replace the default error handler
out = self.c_locale_get_error_handler(locale, encoding=':ignore')
self.assertEqual(out,
'stdin: ignore\n'
'stdout: ignore\n'
'stderr: backslashreplace\n')
# force the encoding
out = self.c_locale_get_error_handler(locale, encoding='iso8859-1')
self.assertEqual(out,
'stdin: strict\n'
'stdout: strict\n'
'stderr: backslashreplace\n')
out = self.c_locale_get_error_handler(locale, encoding='iso8859-1:')
self.assertEqual(out,
'stdin: strict\n'
'stdout: strict\n'
'stderr: backslashreplace\n')
# have no any effect
out = self.c_locale_get_error_handler(locale, encoding=':')
self.assertEqual(out,
'stdin: surrogateescape\n'
'stdout: surrogateescape\n'
'stderr: backslashreplace\n')
out = self.c_locale_get_error_handler(locale, encoding='')
self.assertEqual(out,
'stdin: surrogateescape\n'
'stdout: surrogateescape\n'
'stderr: backslashreplace\n')
def test_c_locale_surrogateescape(self):
self.check_locale_surrogateescape('C')
def test_posix_locale_surrogateescape(self):
self.check_locale_surrogateescape('POSIX')
def test_implementation(self):
# This test applies to all implementations equally.
levels = {'alpha': 0xA, 'beta': 0xB, 'candidate': 0xC, 'final': 0xF}
self.assertTrue(hasattr(sys.implementation, 'name'))
self.assertTrue(hasattr(sys.implementation, 'version'))
self.assertTrue(hasattr(sys.implementation, 'hexversion'))
self.assertTrue(hasattr(sys.implementation, 'cache_tag'))
version = sys.implementation.version
self.assertEqual(version[:2], (version.major, version.minor))
hexversion = (version.major << 24 | version.minor << 16 |
version.micro << 8 | levels[version.releaselevel] << 4 |
version.serial << 0)
self.assertEqual(sys.implementation.hexversion, hexversion)
# PEP 421 requires that .name be lower case.
self.assertEqual(sys.implementation.name,
sys.implementation.name.lower())
@test.support.cpython_only
def test_debugmallocstats(self):
# Test sys._debugmallocstats()
from test.support.script_helper import assert_python_ok
args = ['-c', 'import sys; sys._debugmallocstats()']
ret, out, err = assert_python_ok(*args)
self.assertIn(b"free PyDictObjects", err)
# The function has no parameter
self.assertRaises(TypeError, sys._debugmallocstats, True)
@unittest.skipUnless(hasattr(sys, "getallocatedblocks"),
"sys.getallocatedblocks unavailable on this build")
def test_getallocatedblocks(self):
try:
import _testcapi
except ImportError:
with_pymalloc = support.with_pymalloc()
else:
try:
alloc_name = _testcapi.pymem_getallocatorsname()
except RuntimeError as exc:
# "cannot get allocators name" (ex: tracemalloc is used)
with_pymalloc = True
else:
with_pymalloc = (alloc_name in ('pymalloc', 'pymalloc_debug'))
# Some sanity checks
a = sys.getallocatedblocks()
self.assertIs(type(a), int)
if with_pymalloc:
self.assertGreater(a, 0)
else:
# When WITH_PYMALLOC isn't available, we don't know anything
# about the underlying implementation: the function might
# return 0 or something greater.
self.assertGreaterEqual(a, 0)
try:
# While we could imagine a Python session where the number of
# multiple buffer objects would exceed the sharing of references,
# it is unlikely to happen in a normal test run.
self.assertLess(a, sys.gettotalrefcount())
except AttributeError:
# gettotalrefcount() not available
pass
gc.collect()
b = sys.getallocatedblocks()
self.assertLessEqual(b, a)
gc.collect()
c = sys.getallocatedblocks()
self.assertIn(c, range(b - 50, b + 50))
def test_is_finalizing(self):
self.assertIs(sys.is_finalizing(), False)
# Don't use the atexit module because _Py_Finalizing is only set
# after calling atexit callbacks
code = """if 1:
import sys
class AtExit:
is_finalizing = sys.is_finalizing
print = print
def __del__(self):
self.print(self.is_finalizing(), flush=True)
# Keep a reference in the __main__ module namespace, so the
# AtExit destructor will be called at Python exit
ref = AtExit()
"""
rc, stdout, stderr = assert_python_ok('-c', code)
self.assertEqual(stdout.rstrip(), b'True')
def test_issue20602(self):
# sys.flags and sys.float_info were wiped during shutdown.
code = """if 1:
import sys
class A:
def __del__(self, sys=sys):
print(sys.flags)
print(sys.float_info)
a = A()
"""
rc, out, err = assert_python_ok('-c', code)
out = out.splitlines()
self.assertIn(b'sys.flags', out[0])
self.assertIn(b'sys.float_info', out[1])
def test_sys_ignores_cleaning_up_user_data(self):
code = """if 1:
import struct, sys
class C:
def __init__(self):
self.pack = struct.pack
def __del__(self):
self.pack('I', -42)
sys.x = C()
"""
rc, stdout, stderr = assert_python_ok('-c', code)
self.assertEqual(rc, 0)
self.assertEqual(stdout.rstrip(), b"")
self.assertEqual(stderr.rstrip(), b"")
@unittest.skipUnless(hasattr(sys, 'getandroidapilevel'),
'need sys.getandroidapilevel()')
def test_getandroidapilevel(self):
level = sys.getandroidapilevel()
self.assertIsInstance(level, int)
self.assertGreater(level, 0)
def test_sys_tracebacklimit(self):
code = """if 1:
import sys
def f1():
1 / 0
def f2():
f1()
sys.tracebacklimit = %r
f2()
"""
def check(tracebacklimit, expected):
p = subprocess.Popen([sys.executable, '-c', code % tracebacklimit],
stderr=subprocess.PIPE)
out = p.communicate()[1]
self.assertEqual(out.splitlines(), expected)
traceback = [
b'Traceback (most recent call last):',
b' File "<string>", line 8, in <module>',
b' File "<string>", line 6, in f2',
b' File "<string>", line 4, in f1',
b'ZeroDivisionError: division by zero'
]
check(10, traceback)
check(3, traceback)
check(2, traceback[:1] + traceback[2:])
check(1, traceback[:1] + traceback[3:])
check(0, [traceback[-1]])
check(-1, [traceback[-1]])
check(1<<1000, traceback)
check(-1<<1000, [traceback[-1]])
check(None, traceback)
def test_no_duplicates_in_meta_path(self):
self.assertEqual(len(sys.meta_path), len(set(sys.meta_path)))
@unittest.skipUnless(hasattr(sys, "_enablelegacywindowsfsencoding"),
'needs sys._enablelegacywindowsfsencoding()')
def test__enablelegacywindowsfsencoding(self):
code = ('import sys',
'sys._enablelegacywindowsfsencoding()',
'print(sys.getfilesystemencoding(), sys.getfilesystemencodeerrors())')
rc, out, err = assert_python_ok('-c', '; '.join(code))
out = out.decode('ascii', 'replace').rstrip()
self.assertEqual(out, 'mbcs replace')
def test_orig_argv(self):
code = textwrap.dedent('''
import sys
print(sys.argv)
print(sys.orig_argv)
''')
args = [sys.executable, '-I', '-X', 'utf8', '-c', code, 'arg']
proc = subprocess.run(args, check=True, capture_output=True, text=True)
expected = [
repr(['-c', 'arg']), # sys.argv
repr(args), # sys.orig_argv
]
self.assertEqual(proc.stdout.rstrip().splitlines(), expected,
proc)
@test.support.cpython_only
class UnraisableHookTest(unittest.TestCase):
def write_unraisable_exc(self, exc, err_msg, obj):
import _testcapi
import types
err_msg2 = f"Exception ignored {err_msg}"
try:
_testcapi.write_unraisable_exc(exc, err_msg, obj)
return types.SimpleNamespace(exc_type=type(exc),
exc_value=exc,
exc_traceback=exc.__traceback__,
err_msg=err_msg2,
object=obj)
finally:
# Explicitly break any reference cycle
exc = None
def test_original_unraisablehook(self):
for err_msg in (None, "original hook"):
with self.subTest(err_msg=err_msg):
obj = "an object"
with test.support.captured_output("stderr") as stderr:
with test.support.swap_attr(sys, 'unraisablehook',
sys.__unraisablehook__):
self.write_unraisable_exc(ValueError(42), err_msg, obj)
err = stderr.getvalue()
if err_msg is not None:
self.assertIn(f'Exception ignored {err_msg}: {obj!r}\n', err)
else:
self.assertIn(f'Exception ignored in: {obj!r}\n', err)
self.assertIn('Traceback (most recent call last):\n', err)
self.assertIn('ValueError: 42\n', err)
def test_original_unraisablehook_err(self):
# bpo-22836: PyErr_WriteUnraisable() should give sensible reports
class BrokenDel:
def __del__(self):
exc = ValueError("del is broken")
# The following line is included in the traceback report:
raise exc
class BrokenStrException(Exception):
def __str__(self):
raise Exception("str() is broken")
class BrokenExceptionDel:
def __del__(self):
exc = BrokenStrException()
# The following line is included in the traceback report:
raise exc
for test_class in (BrokenDel, BrokenExceptionDel):
with self.subTest(test_class):
obj = test_class()
with test.support.captured_stderr() as stderr, \
test.support.swap_attr(sys, 'unraisablehook',
sys.__unraisablehook__):
# Trigger obj.__del__()
del obj
report = stderr.getvalue()
self.assertIn("Exception ignored", report)
self.assertIn(test_class.__del__.__qualname__, report)
self.assertIn("test_sys.py", report)
self.assertIn("raise exc", report)
if test_class is BrokenExceptionDel:
self.assertIn("BrokenStrException", report)
self.assertIn("<exception str() failed>", report)
else:
self.assertIn("ValueError", report)
self.assertIn("del is broken", report)
self.assertTrue(report.endswith("\n"))
def test_original_unraisablehook_wrong_type(self):
exc = ValueError(42)
with test.support.swap_attr(sys, 'unraisablehook',
sys.__unraisablehook__):
with self.assertRaises(TypeError):
sys.unraisablehook(exc)
def test_custom_unraisablehook(self):
hook_args = None
def hook_func(args):
nonlocal hook_args
hook_args = args
obj = object()
try:
with test.support.swap_attr(sys, 'unraisablehook', hook_func):
expected = self.write_unraisable_exc(ValueError(42),
"custom hook", obj)
for attr in "exc_type exc_value exc_traceback err_msg object".split():
self.assertEqual(getattr(hook_args, attr),
getattr(expected, attr),
(hook_args, expected))
finally:
# expected and hook_args contain an exception: break reference cycle
expected = None
hook_args = None
def test_custom_unraisablehook_fail(self):
def hook_func(*args):
raise Exception("hook_func failed")
with test.support.captured_output("stderr") as stderr:
with test.support.swap_attr(sys, 'unraisablehook', hook_func):
self.write_unraisable_exc(ValueError(42),
"custom hook fail", None)
err = stderr.getvalue()
self.assertIn(f'Exception ignored in sys.unraisablehook: '
f'{hook_func!r}\n',
err)
self.assertIn('Traceback (most recent call last):\n', err)
self.assertIn('Exception: hook_func failed\n', err)
@test.support.cpython_only
class SizeofTest(unittest.TestCase):
def setUp(self):
self.P = struct.calcsize('P')
self.longdigit = sys.int_info.sizeof_digit
import _testinternalcapi
self.gc_headsize = _testinternalcapi.SIZEOF_PYGC_HEAD
check_sizeof = test.support.check_sizeof
def test_gc_head_size(self):
# Check that the gc header size is added to objects tracked by the gc.
vsize = test.support.calcvobjsize
gc_header_size = self.gc_headsize
# bool objects are not gc tracked
self.assertEqual(sys.getsizeof(True), vsize('') + self.longdigit)
# but lists are
self.assertEqual(sys.getsizeof([]), vsize('Pn') + gc_header_size)
def test_errors(self):
class BadSizeof:
def __sizeof__(self):
raise ValueError
self.assertRaises(ValueError, sys.getsizeof, BadSizeof())
class InvalidSizeof:
def __sizeof__(self):
return None
self.assertRaises(TypeError, sys.getsizeof, InvalidSizeof())
sentinel = ["sentinel"]
self.assertIs(sys.getsizeof(InvalidSizeof(), sentinel), sentinel)
class FloatSizeof:
def __sizeof__(self):
return 4.5
self.assertRaises(TypeError, sys.getsizeof, FloatSizeof())
self.assertIs(sys.getsizeof(FloatSizeof(), sentinel), sentinel)
class OverflowSizeof(int):
def __sizeof__(self):
return int(self)
self.assertEqual(sys.getsizeof(OverflowSizeof(sys.maxsize)),
sys.maxsize + self.gc_headsize)
with self.assertRaises(OverflowError):
sys.getsizeof(OverflowSizeof(sys.maxsize + 1))
with self.assertRaises(ValueError):
sys.getsizeof(OverflowSizeof(-1))
with self.assertRaises((ValueError, OverflowError)):
sys.getsizeof(OverflowSizeof(-sys.maxsize - 1))
def test_default(self):
size = test.support.calcvobjsize
self.assertEqual(sys.getsizeof(True), size('') + self.longdigit)
self.assertEqual(sys.getsizeof(True, -1), size('') + self.longdigit)
def test_objecttypes(self):
# check all types defined in Objects/
calcsize = struct.calcsize
size = test.support.calcobjsize
vsize = test.support.calcvobjsize
check = self.check_sizeof
# bool
check(True, vsize('') + self.longdigit)
# buffer
# XXX
# builtin_function_or_method
check(len, size('5P'))
# bytearray
samples = [b'', b'u'*100000]
for sample in samples:
x = bytearray(sample)
check(x, vsize('n2Pi') + x.__alloc__())
# bytearray_iterator
check(iter(bytearray()), size('nP'))
# bytes
check(b'', vsize('n') + 1)
check(b'x' * 10, vsize('n') + 11)
# cell
def get_cell():
x = 42
def inner():
return x
return inner
check(get_cell().__closure__[0], size('P'))
# code
def check_code_size(a, expected_size):
self.assertGreaterEqual(sys.getsizeof(a), expected_size)
check_code_size(get_cell().__code__, size('6i13P'))
check_code_size(get_cell.__code__, size('6i13P'))
def get_cell2(x):
def inner():
return x
return inner
check_code_size(get_cell2.__code__, size('6i13P') + calcsize('n'))
# complex
check(complex(0,1), size('2d'))
# method_descriptor (descriptor object)
check(str.lower, size('3PPP'))
# classmethod_descriptor (descriptor object)
# XXX
# member_descriptor (descriptor object)
import datetime
check(datetime.timedelta.days, size('3PP'))
# getset_descriptor (descriptor object)
import collections
check(collections.defaultdict.default_factory, size('3PP'))
# wrapper_descriptor (descriptor object)
check(int.__add__, size('3P2P'))
# method-wrapper (descriptor object)
check({}.__iter__, size('2P'))
# empty dict
check({}, size('nQ2P'))
# dict
check({"a": 1}, size('nQ2P') + calcsize('2nP2n') + 8 + (8*2//3)*calcsize('n2P'))
longdict = {1:1, 2:2, 3:3, 4:4, 5:5, 6:6, 7:7, 8:8}
check(longdict, size('nQ2P') + calcsize('2nP2n') + 16 + (16*2//3)*calcsize('n2P'))
# dictionary-keyview
check({}.keys(), size('P'))
# dictionary-valueview
check({}.values(), size('P'))
# dictionary-itemview
check({}.items(), size('P'))
# dictionary iterator
check(iter({}), size('P2nPn'))
# dictionary-keyiterator
check(iter({}.keys()), size('P2nPn'))
# dictionary-valueiterator
check(iter({}.values()), size('P2nPn'))
# dictionary-itemiterator
check(iter({}.items()), size('P2nPn'))
# dictproxy
class C(object): pass
check(C.__dict__, size('P'))
# BaseException
check(BaseException(), size('5Pb'))
# UnicodeEncodeError
check(UnicodeEncodeError("", "", 0, 0, ""), size('5Pb 2P2nP'))
# UnicodeDecodeError
check(UnicodeDecodeError("", b"", 0, 0, ""), size('5Pb 2P2nP'))
# UnicodeTranslateError
check(UnicodeTranslateError("", 0, 1, ""), size('5Pb 2P2nP'))
# ellipses
check(Ellipsis, size(''))
# EncodingMap
import codecs, encodings.iso8859_3
x = codecs.charmap_build(encodings.iso8859_3.decoding_table)
check(x, size('32B2iB'))
# enumerate
check(enumerate([]), size('n3P'))
# reverse
check(reversed(''), size('nP'))
# float
check(float(0), size('d'))
# sys.floatinfo
check(sys.float_info, vsize('') + self.P * len(sys.float_info))
# frame
import inspect
CO_MAXBLOCKS = 20
x = inspect.currentframe()
ncells = len(x.f_code.co_cellvars)
nfrees = len(x.f_code.co_freevars)
extras = x.f_code.co_stacksize + x.f_code.co_nlocals +\
ncells + nfrees - 1
check(x, vsize('4Pi2c4P3ic' + CO_MAXBLOCKS*'3i' + 'P' + extras*'P'))
# function
def func(): pass
check(func, size('13P'))
class c():
@staticmethod
def foo():
pass
@classmethod
def bar(cls):
pass
# staticmethod
check(foo, size('PP'))
# classmethod
check(bar, size('PP'))
# generator
def get_gen(): yield 1
check(get_gen(), size('P2PPP4P'))
# iterator
check(iter('abc'), size('lP'))
# callable-iterator
import re
check(re.finditer('',''), size('2P'))
# list
samples = [[], [1,2,3], ['1', '2', '3']]
for sample in samples:
check(list(sample), vsize('Pn') + len(sample)*self.P)
# sortwrapper (list)
# XXX
# cmpwrapper (list)
# XXX
# listiterator (list)
check(iter([]), size('lP'))
# listreverseiterator (list)
check(reversed([]), size('nP'))
# int
check(0, vsize(''))
check(1, vsize('') + self.longdigit)
check(-1, vsize('') + self.longdigit)
PyLong_BASE = 2**sys.int_info.bits_per_digit
check(int(PyLong_BASE), vsize('') + 2*self.longdigit)
check(int(PyLong_BASE**2-1), vsize('') + 2*self.longdigit)
check(int(PyLong_BASE**2), vsize('') + 3*self.longdigit)
# module
check(unittest, size('PnPPP'))
# None
check(None, size(''))
# NotImplementedType
check(NotImplemented, size(''))
# object
check(object(), size(''))
# property (descriptor object)
class C(object):
def getx(self): return self.__x
def setx(self, value): self.__x = value
def delx(self): del self.__x
x = property(getx, setx, delx, "")
check(x, size('4Pi'))
# PyCapsule
# XXX
# rangeiterator
check(iter(range(1)), size('4l'))
# reverse
check(reversed(''), size('nP'))
# range
check(range(1), size('4P'))
check(range(66000), size('4P'))
# set
# frozenset
PySet_MINSIZE = 8
samples = [[], range(10), range(50)]
s = size('3nP' + PySet_MINSIZE*'nP' + '2nP')
for sample in samples:
minused = len(sample)
if minused == 0: tmp = 1
# the computation of minused is actually a bit more complicated
# but this suffices for the sizeof test
minused = minused*2
newsize = PySet_MINSIZE
while newsize <= minused:
newsize = newsize << 1
if newsize <= 8:
check(set(sample), s)
check(frozenset(sample), s)
else:
check(set(sample), s + newsize*calcsize('nP'))
check(frozenset(sample), s + newsize*calcsize('nP'))
# setiterator
check(iter(set()), size('P3n'))
# slice
check(slice(0), size('3P'))
# super
check(super(int), size('3P'))
# tuple
check((), vsize(''))
check((1,2,3), vsize('') + 3*self.P)
# type
# static type: PyTypeObject
fmt = 'P2nPI13Pl4Pn9Pn11PIPP'
s = vsize(fmt)
check(int, s)
# class
s = vsize(fmt + # PyTypeObject
'3P' # PyAsyncMethods
'36P' # PyNumberMethods
'3P' # PyMappingMethods
'10P' # PySequenceMethods
'2P' # PyBufferProcs
'5P')
class newstyleclass(object): pass
# Separate block for PyDictKeysObject with 8 keys and 5 entries
check(newstyleclass, s + calcsize("2nP2n0P") + 8 + 5*calcsize("n2P"))
# dict with shared keys
check(newstyleclass().__dict__, size('nQ2P') + 5*self.P)
o = newstyleclass()
o.a = o.b = o.c = o.d = o.e = o.f = o.g = o.h = 1
# Separate block for PyDictKeysObject with 16 keys and 10 entries
check(newstyleclass, s + calcsize("2nP2n0P") + 16 + 10*calcsize("n2P"))
# dict with shared keys
check(newstyleclass().__dict__, size('nQ2P') + 10*self.P)
# unicode
# each tuple contains a string and its expected character size
# don't put any static strings here, as they may contain
# wchar_t or UTF-8 representations
samples = ['1'*100, '\xff'*50,
'\u0100'*40, '\uffff'*100,
'\U00010000'*30, '\U0010ffff'*100]
asciifields = "nnbP"
compactfields = asciifields + "nPn"
unicodefields = compactfields + "P"
for s in samples:
maxchar = ord(max(s))
if maxchar < 128:
L = size(asciifields) + len(s) + 1
elif maxchar < 256:
L = size(compactfields) + len(s) + 1
elif maxchar < 65536:
L = size(compactfields) + 2*(len(s) + 1)
else:
L = size(compactfields) + 4*(len(s) + 1)
check(s, L)
# verify that the UTF-8 size is accounted for
s = chr(0x4000) # 4 bytes canonical representation
check(s, size(compactfields) + 4)
# compile() will trigger the generation of the UTF-8
# representation as a side effect
compile(s, "<stdin>", "eval")
check(s, size(compactfields) + 4 + 4)
# TODO: add check that forces the presence of wchar_t representation
# TODO: add check that forces layout of unicodefields
# weakref
import weakref
check(weakref.ref(int), size('2Pn2P'))
# weakproxy
# XXX
# weakcallableproxy
check(weakref.proxy(int), size('2Pn2P'))
def check_slots(self, obj, base, extra):
expected = sys.getsizeof(base) + struct.calcsize(extra)
if gc.is_tracked(obj) and not gc.is_tracked(base):
expected += self.gc_headsize
self.assertEqual(sys.getsizeof(obj), expected)
def test_slots(self):
# check all subclassable types defined in Objects/ that allow
# non-empty __slots__
check = self.check_slots
class BA(bytearray):
__slots__ = 'a', 'b', 'c'
check(BA(), bytearray(), '3P')
class D(dict):
__slots__ = 'a', 'b', 'c'
check(D(x=[]), {'x': []}, '3P')
class L(list):
__slots__ = 'a', 'b', 'c'
check(L(), [], '3P')
class S(set):
__slots__ = 'a', 'b', 'c'
check(S(), set(), '3P')
class FS(frozenset):
__slots__ = 'a', 'b', 'c'
check(FS(), frozenset(), '3P')
from collections import OrderedDict
class OD(OrderedDict):
__slots__ = 'a', 'b', 'c'
check(OD(x=[]), OrderedDict(x=[]), '3P')
def test_pythontypes(self):
# check all types defined in Python/
size = test.support.calcobjsize
vsize = test.support.calcvobjsize
check = self.check_sizeof
# _ast.AST
import _ast
check(_ast.AST(), size('P'))
try:
raise TypeError
except TypeError:
tb = sys.exc_info()[2]
# traceback
if tb is not None:
check(tb, size('2P2i'))
# symtable entry
# XXX
# sys.flags
check(sys.flags, vsize('') + self.P * len(sys.flags))
def test_asyncgen_hooks(self):
old = sys.get_asyncgen_hooks()
self.assertIsNone(old.firstiter)
self.assertIsNone(old.finalizer)
firstiter = lambda *a: None
sys.set_asyncgen_hooks(firstiter=firstiter)
hooks = sys.get_asyncgen_hooks()
self.assertIs(hooks.firstiter, firstiter)
self.assertIs(hooks[0], firstiter)
self.assertIs(hooks.finalizer, None)
self.assertIs(hooks[1], None)
finalizer = lambda *a: None
sys.set_asyncgen_hooks(finalizer=finalizer)
hooks = sys.get_asyncgen_hooks()
self.assertIs(hooks.firstiter, firstiter)
self.assertIs(hooks[0], firstiter)
self.assertIs(hooks.finalizer, finalizer)
self.assertIs(hooks[1], finalizer)
sys.set_asyncgen_hooks(*old)
cur = sys.get_asyncgen_hooks()
self.assertIsNone(cur.firstiter)
self.assertIsNone(cur.finalizer)
if __name__ == "__main__":
unittest.main()