FM / python3.8

/snap/core20/2866/usr/lib/python3.8

Name	Size	Mode	Actions
asyncio/	-	0755	rm
collections/	-	0755	rm
concurrent/	-	0755	rm
ctypes/	-	0755	rm
curses/	-	0755	rm
dbm/	-	0755	rm
distutils/	-	0755	rm
email/	-	0755	rm
encodings/	-	0755	rm
html/	-	0755	rm
http/	-	0755	rm
importlib/	-	0755	rm
json/	-	0755	rm
lib-dynload/	-	0755	rm
lib2to3/	-	0755	rm
logging/	-	0755	rm
multiprocessing/	-	0755	rm
pydoc_data/	-	0755	rm
sqlite3/	-	0755	rm
test/	-	0755	rm
unittest/	-	0755	rm
urllib/	-	0755	rm
venv/	-	0755	rm
wsgiref/	-	0755	rm
xml/	-	0755	rm
xmlrpc/	-	0755	rm
__pycache__/	-	0755	rm
abc.py	4489	0644	edit dl rm
aifc.py	32814	0644	edit dl rm
antigravity.py	477	0644	edit dl rm
argparse.py	96311	0644	edit dl rm
ast.py	19234	0644	edit dl rm
asynchat.py	11328	0644	edit dl rm
asyncore.py	20094	0644	edit dl rm
base64.py	20382	0755	edit dl rm
bdb.py	32056	0644	edit dl rm
binhex.py	13954	0644	edit dl rm
bisect.py	2214	0644	edit dl rm
bz2.py	12558	0644	edit dl rm
calendar.py	24832	0644	edit dl rm
cgi.py	33932	0755	edit dl rm
cgitb.py	12096	0644	edit dl rm
chunk.py	5435	0644	edit dl rm
cmd.py	14860	0644	edit dl rm
code.py	10622	0644	edit dl rm
codecs.py	36667	0644	edit dl rm
codeop.py	6330	0644	edit dl rm
colorsys.py	4064	0644	edit dl rm
compileall.py	13678	0644	edit dl rm
configparser.py	54374	0644	edit dl rm
contextlib.py	24995	0644	edit dl rm
contextvars.py	129	0644	edit dl rm
copy.py	8661	0644	edit dl rm
copyreg.py	7135	0644	edit dl rm
cProfile.py	6998	0755	edit dl rm
crypt.py	3610	0644	edit dl rm
csv.py	16144	0644	edit dl rm
dataclasses.py	49973	0644	edit dl rm
datetime.py	88287	0644	edit dl rm
decimal.py	320	0644	edit dl rm
difflib.py	84058	0644	edit dl rm
dis.py	20570	0644	edit dl rm
doctest.py	104543	0644	edit dl rm
dummy_threading.py	2815	0644	edit dl rm
enum.py	38136	0644	edit dl rm
filecmp.py	9830	0644	edit dl rm
fileinput.py	14709	0644	edit dl rm
fnmatch.py	4079	0644	edit dl rm
formatter.py	15143	0644	edit dl rm
fractions.py	24329	0644	edit dl rm
ftplib.py	35129	0644	edit dl rm
functools.py	37406	0644	edit dl rm
genericpath.py	4975	0644	edit dl rm
getopt.py	7489	0644	edit dl rm
getpass.py	5994	0644	edit dl rm
gettext.py	27565	0644	edit dl rm
glob.py	5697	0644	edit dl rm
gzip.py	21413	0644	edit dl rm
hashlib.py	9730	0644	edit dl rm
heapq.py	22877	0644	edit dl rm
hmac.py	6629	0644	edit dl rm
imaplib.py	53606	0644	edit dl rm
imghdr.py	3808	0644	edit dl rm
imp.py	10536	0644	edit dl rm
inspect.py	118550	0644	edit dl rm
io.py	3541	0644	edit dl rm
ipaddress.py	76336	0644	edit dl rm
keyword.py	945	0644	edit dl rm
LICENSE.txt	13925	0644	edit dl rm
linecache.py	5330	0644	edit dl rm
locale.py	78195	0644	edit dl rm
lzma.py	12983	0644	edit dl rm
mailbox.py	78661	0644	edit dl rm
mailcap.py	9067	0644	edit dl rm
mimetypes.py	21664	0644	edit dl rm
modulefinder.py	24430	0644	edit dl rm
netrc.py	5566	0644	edit dl rm
nntplib.py	43261	0644	edit dl rm
ntpath.py	25814	0644	edit dl rm
nturl2path.py	2887	0644	edit dl rm
numbers.py	10244	0644	edit dl rm
opcode.py	5808	0644	edit dl rm
operator.py	10711	0644	edit dl rm
optparse.py	60369	0644	edit dl rm
os.py	38995	0644	edit dl rm
pathlib.py	52610	0644	edit dl rm
pdb.py	62738	0755	edit dl rm
pickle.py	64467	0644	edit dl rm
pickletools.py	93486	0644	edit dl rm
pipes.py	8916	0644	edit dl rm
pkgutil.py	21461	0644	edit dl rm
platform.py	40425	0755	edit dl rm
plistlib.py	32460	0644	edit dl rm
poplib.py	15077	0644	edit dl rm
posixpath.py	15500	0644	edit dl rm
pprint.py	21484	0644	edit dl rm
profile.py	23534	0755	edit dl rm
pstats.py	27345	0644	edit dl rm
pty.py	4807	0644	edit dl rm
pyclbr.py	15255	0644	edit dl rm
pydoc.py	106863	0755	edit dl rm
py_compile.py	8148	0644	edit dl rm
queue.py	11356	0644	edit dl rm
quopri.py	7252	0755	edit dl rm
random.py	28802	0644	edit dl rm
re.py	15861	0644	edit dl rm
reprlib.py	5267	0644	edit dl rm
rlcompleter.py	7097	0644	edit dl rm
runpy.py	12052	0644	edit dl rm
sched.py	6442	0644	edit dl rm
secrets.py	2038	0644	edit dl rm
selectors.py	18561	0644	edit dl rm
shelve.py	8527	0644	edit dl rm
shlex.py	13325	0644	edit dl rm
shutil.py	51474	0644	edit dl rm
signal.py	2273	0644	edit dl rm
site.py	22336	0644	edit dl rm
sitecustomize.py	-	0	edit dl rm
smtpd.py	34709	0755	edit dl rm
smtplib.py	44804	0755	edit dl rm
sndhdr.py	7099	0644	edit dl rm
socket.py	35243	0644	edit dl rm
socketserver.py	27296	0644	edit dl rm
sre_compile.py	26695	0644	edit dl rm
sre_constants.py	7154	0644	edit dl rm
sre_parse.py	40230	0644	edit dl rm
ssl.py	52363	0644	edit dl rm
stat.py	5485	0644	edit dl rm
statistics.py	39690	0644	edit dl rm
string.py	10535	0644	edit dl rm
stringprep.py	12917	0644	edit dl rm
struct.py	257	0644	edit dl rm
subprocess.py	77330	0644	edit dl rm
sunau.py	18375	0644	edit dl rm
symbol.py	2109	0644	edit dl rm
symtable.py	8021	0644	edit dl rm
sysconfig.py	25035	0644	edit dl rm
tabnanny.py	11406	0755	edit dl rm
tarfile.py	95580	0755	edit dl rm
telnetlib.py	23254	0644	edit dl rm
tempfile.py	32920	0644	edit dl rm
textwrap.py	19407	0644	edit dl rm
this.py	1003	0644	edit dl rm
threading.py	50820	0644	edit dl rm
timeit.py	13480	0755	edit dl rm
token.py	2368	0644	edit dl rm
tokenize.py	25841	0644	edit dl rm
trace.py	29858	0755	edit dl rm
traceback.py	23611	0644	edit dl rm
tracemalloc.py	17076	0644	edit dl rm
tty.py	879	0644	edit dl rm
turtle.py	143716	0644	edit dl rm
types.py	9713	0644	edit dl rm
typing.py	68962	0644	edit dl rm
uu.py	6957	0755	edit dl rm
uuid.py	30466	0644	edit dl rm
warnings.py	19688	0644	edit dl rm
wave.py	18230	0644	edit dl rm
weakref.py	21387	0644	edit dl rm
webbrowser.py	24083	0755	edit dl rm
xdrlib.py	5913	0644	edit dl rm
zipapp.py	7535	0644	edit dl rm
zipfile.py	89135	0644	edit dl rm
zipimport.py	30765	0644	edit dl rm
_bootlocale.py	1801	0644	edit dl rm
_collections_abc.py	26100	0644	edit dl rm
_compat_pickle.py	8749	0644	edit dl rm
_compression.py	5340	0644	edit dl rm
_dummy_thread.py	6027	0644	edit dl rm
_markupbase.py	14598	0644	edit dl rm
_osx_support.py	21774	0644	edit dl rm
_pydecimal.py	228666	0644	edit dl rm
_pyio.py	93177	0644	edit dl rm
_py_abc.py	6189	0644	edit dl rm
_sitebuiltins.py	3115	0644	edit dl rm
_strptime.py	25268	0644	edit dl rm
_sysconfigdata__linux_x86_64-linux-gnu.py	25834	0644	edit dl rm
_sysconfigdata__x86_64-linux-gnu.py	25834	0644	edit dl rm
_threading_local.py	7220	0644	edit dl rm
_weakrefset.py	5735	0644	edit dl rm
__future__.py	5147	0644	edit dl rm
__phello__.foo.py	64	0644	edit dl rm

Edit: /snap/core20/2866/usr/lib/python3.8/contextlib.py (24995B)

"""Utilities for with-statement contexts.  See PEP 343."""
import abc
import sys
import _collections_abc
from collections import deque
from functools import wraps
from types import MethodType

__all__ = ["asynccontextmanager", "contextmanager", "closing", "nullcontext",
           "AbstractContextManager", "AbstractAsyncContextManager",
           "AsyncExitStack", "ContextDecorator", "ExitStack",
           "redirect_stdout", "redirect_stderr", "suppress"]

class AbstractContextManager(abc.ABC):

"""An abstract base class for context managers."""

def __enter__(self):
        """Return `self` upon entering the runtime context."""
        return self

@abc.abstractmethod
    def __exit__(self, exc_type, exc_value, traceback):
        """Raise any exception triggered within the runtime context."""
        return None

@classmethod
    def __subclasshook__(cls, C):
        if cls is AbstractContextManager:
            return _collections_abc._check_methods(C, "__enter__", "__exit__")
        return NotImplemented

class AbstractAsyncContextManager(abc.ABC):

"""An abstract base class for asynchronous context managers."""

async def __aenter__(self):
        """Return `self` upon entering the runtime context."""
        return self

@abc.abstractmethod
    async def __aexit__(self, exc_type, exc_value, traceback):
        """Raise any exception triggered within the runtime context."""
        return None

@classmethod
    def __subclasshook__(cls, C):
        if cls is AbstractAsyncContextManager:
            return _collections_abc._check_methods(C, "__aenter__",
                                                   "__aexit__")
        return NotImplemented

class ContextDecorator(object):
    "A base class or mixin that enables context managers to work as decorators."

def _recreate_cm(self):
        """Return a recreated instance of self.

Allows an otherwise one-shot context manager like
        _GeneratorContextManager to support use as
        a decorator via implicit recreation.

This is a private interface just for _GeneratorContextManager.
        See issue #11647 for details.
        """
        return self

def __call__(self, func):
        @wraps(func)
        def inner(*args, **kwds):
            with self._recreate_cm():
                return func(*args, **kwds)
        return inner

class _GeneratorContextManagerBase:
    """Shared functionality for @contextmanager and @asynccontextmanager."""

def __init__(self, func, args, kwds):
        self.gen = func(*args, **kwds)
        self.func, self.args, self.kwds = func, args, kwds
        # Issue 19330: ensure context manager instances have good docstrings
        doc = getattr(func, "__doc__", None)
        if doc is None:
            doc = type(self).__doc__
        self.__doc__ = doc
        # Unfortunately, this still doesn't provide good help output when
        # inspecting the created context manager instances, since pydoc
        # currently bypasses the instance docstring and shows the docstring
        # for the class instead.
        # See http://bugs.python.org/issue19404 for more details.

class _GeneratorContextManager(_GeneratorContextManagerBase,
                               AbstractContextManager,
                               ContextDecorator):
    """Helper for @contextmanager decorator."""

def _recreate_cm(self):
        # _GCM instances are one-shot context managers, so the
        # CM must be recreated each time a decorated function is
        # called
        return self.__class__(self.func, self.args, self.kwds)

def __enter__(self):
        # do not keep args and kwds alive unnecessarily
        # they are only needed for recreation, which is not possible anymore
        del self.args, self.kwds, self.func
        try:
            return next(self.gen)
        except StopIteration:
            raise RuntimeError("generator didn't yield") from None

def __exit__(self, type, value, traceback):
        if type is None:
            try:
                next(self.gen)
            except StopIteration:
                return False
            else:
                raise RuntimeError("generator didn't stop")
        else:
            if value is None:
                # Need to force instantiation so we can reliably
                # tell if we get the same exception back
                value = type()
            try:
                self.gen.throw(type, value, traceback)
            except StopIteration as exc:
                # Suppress StopIteration *unless* it's the same exception that
                # was passed to throw().  This prevents a StopIteration
                # raised inside the "with" statement from being suppressed.
                return exc is not value
            except RuntimeError as exc:
                # Don't re-raise the passed in exception. (issue27122)
                if exc is value:
                    return False
                # Likewise, avoid suppressing if a StopIteration exception
                # was passed to throw() and later wrapped into a RuntimeError
                # (see PEP 479).
                if type is StopIteration and exc.__cause__ is value:
                    return False
                raise
            except:
                # only re-raise if it's *not* the exception that was
                # passed to throw(), because __exit__() must not raise
                # an exception unless __exit__() itself failed.  But throw()
                # has to raise the exception to signal propagation, so this
                # fixes the impedance mismatch between the throw() protocol
                # and the __exit__() protocol.
                #
                # This cannot use 'except BaseException as exc' (as in the
                # async implementation) to maintain compatibility with
                # Python 2, where old-style class exceptions are not caught
                # by 'except BaseException'.
                if sys.exc_info()[1] is value:
                    return False
                raise
            raise RuntimeError("generator didn't stop after throw()")

class _AsyncGeneratorContextManager(_GeneratorContextManagerBase,
                                    AbstractAsyncContextManager):
    """Helper for @asynccontextmanager."""

async def __aenter__(self):
        try:
            return await self.gen.__anext__()
        except StopAsyncIteration:
            raise RuntimeError("generator didn't yield") from None

async def __aexit__(self, typ, value, traceback):
        if typ is None:
            try:
                await self.gen.__anext__()
            except StopAsyncIteration:
                return
            else:
                raise RuntimeError("generator didn't stop")
        else:
            if value is None:
                value = typ()
            # See _GeneratorContextManager.__exit__ for comments on subtleties
            # in this implementation
            try:
                await self.gen.athrow(typ, value, traceback)
                raise RuntimeError("generator didn't stop after athrow()")
            except StopAsyncIteration as exc:
                return exc is not value
            except RuntimeError as exc:
                if exc is value:
                    return False
                # Avoid suppressing if a StopIteration exception
                # was passed to throw() and later wrapped into a RuntimeError
                # (see PEP 479 for sync generators; async generators also
                # have this behavior). But do this only if the exception wrapped
                # by the RuntimeError is actully Stop(Async)Iteration (see
                # issue29692).
                if isinstance(value, (StopIteration, StopAsyncIteration)):
                    if exc.__cause__ is value:
                        return False
                raise
            except BaseException as exc:
                if exc is not value:
                    raise

def contextmanager(func):
    """@contextmanager decorator.

Typical usage:

@contextmanager
        def some_generator(<arguments>):
            <setup>
            try:
                yield <value>
            finally:
                <cleanup>

This makes this:

with some_generator(<arguments>) as <variable>:
            <body>

equivalent to this:

<setup>
        try:
            <variable> = <value>
            <body>
        finally:
            <cleanup>
    """
    @wraps(func)
    def helper(*args, **kwds):
        return _GeneratorContextManager(func, args, kwds)
    return helper

def asynccontextmanager(func):
    """@asynccontextmanager decorator.

Typical usage:

@asynccontextmanager
        async def some_async_generator(<arguments>):
            <setup>
            try:
                yield <value>
            finally:
                <cleanup>

This makes this:

async with some_async_generator(<arguments>) as <variable>:
            <body>

equivalent to this:

<setup>
        try:
            <variable> = <value>
            <body>
        finally:
            <cleanup>
    """
    @wraps(func)
    def helper(*args, **kwds):
        return _AsyncGeneratorContextManager(func, args, kwds)
    return helper

class closing(AbstractContextManager):
    """Context to automatically close something at the end of a block.

Code like this:

with closing(<module>.open(<arguments>)) as f:
            <block>

is equivalent to this:

f = <module>.open(<arguments>)
        try:
            <block>
        finally:
            f.close()

"""
    def __init__(self, thing):
        self.thing = thing
    def __enter__(self):
        return self.thing
    def __exit__(self, *exc_info):
        self.thing.close()

class _RedirectStream(AbstractContextManager):

_stream = None

def __init__(self, new_target):
        self._new_target = new_target
        # We use a list of old targets to make this CM re-entrant
        self._old_targets = []

def __enter__(self):
        self._old_targets.append(getattr(sys, self._stream))
        setattr(sys, self._stream, self._new_target)
        return self._new_target

def __exit__(self, exctype, excinst, exctb):
        setattr(sys, self._stream, self._old_targets.pop())

class redirect_stdout(_RedirectStream):
    """Context manager for temporarily redirecting stdout to another file.

# How to send help() to stderr
        with redirect_stdout(sys.stderr):
            help(dir)

# How to write help() to a file
        with open('help.txt', 'w') as f:
            with redirect_stdout(f):
                help(pow)
    """

_stream = "stdout"

class redirect_stderr(_RedirectStream):
    """Context manager for temporarily redirecting stderr to another file."""

_stream = "stderr"

class suppress(AbstractContextManager):
    """Context manager to suppress specified exceptions

After the exception is suppressed, execution proceeds with the next
    statement following the with statement.

with suppress(FileNotFoundError):
             os.remove(somefile)
         # Execution still resumes here if the file was already removed
    """

def __init__(self, *exceptions):
        self._exceptions = exceptions

def __enter__(self):
        pass

def __exit__(self, exctype, excinst, exctb):
        # Unlike isinstance and issubclass, CPython exception handling
        # currently only looks at the concrete type hierarchy (ignoring
        # the instance and subclass checking hooks). While Guido considers
        # that a bug rather than a feature, it's a fairly hard one to fix
        # due to various internal implementation details. suppress provides
        # the simpler issubclass based semantics, rather than trying to
        # exactly reproduce the limitations of the CPython interpreter.
        #
        # See http://bugs.python.org/issue12029 for more details
        return exctype is not None and issubclass(exctype, self._exceptions)

class _BaseExitStack:
    """A base class for ExitStack and AsyncExitStack."""

@staticmethod
    def _create_exit_wrapper(cm, cm_exit):
        return MethodType(cm_exit, cm)

@staticmethod
    def _create_cb_wrapper(callback, /, *args, **kwds):
        def _exit_wrapper(exc_type, exc, tb):
            callback(*args, **kwds)
        return _exit_wrapper

def __init__(self):
        self._exit_callbacks = deque()

def pop_all(self):
        """Preserve the context stack by transferring it to a new instance."""
        new_stack = type(self)()
        new_stack._exit_callbacks = self._exit_callbacks
        self._exit_callbacks = deque()
        return new_stack

def push(self, exit):
        """Registers a callback with the standard __exit__ method signature.

Can suppress exceptions the same way __exit__ method can.
        Also accepts any object with an __exit__ method (registering a call
        to the method instead of the object itself).
        """
        # We use an unbound method rather than a bound method to follow
        # the standard lookup behaviour for special methods.
        _cb_type = type(exit)

try:
            exit_method = _cb_type.__exit__
        except AttributeError:
            # Not a context manager, so assume it's a callable.
            self._push_exit_callback(exit)
        else:
            self._push_cm_exit(exit, exit_method)
        return exit  # Allow use as a decorator.

def enter_context(self, cm):
        """Enters the supplied context manager.

If successful, also pushes its __exit__ method as a callback and
        returns the result of the __enter__ method.
        """
        # We look up the special methods on the type to match the with
        # statement.
        _cm_type = type(cm)
        _exit = _cm_type.__exit__
        result = _cm_type.__enter__(cm)
        self._push_cm_exit(cm, _exit)
        return result

def callback(*args, **kwds):
        """Registers an arbitrary callback and arguments.

Cannot suppress exceptions.
        """
        if len(args) >= 2:
            self, callback, *args = args
        elif not args:
            raise TypeError("descriptor 'callback' of '_BaseExitStack' object "
                            "needs an argument")
        elif 'callback' in kwds:
            callback = kwds.pop('callback')
            self, *args = args
            import warnings
            warnings.warn("Passing 'callback' as keyword argument is deprecated",
                          DeprecationWarning, stacklevel=2)
        else:
            raise TypeError('callback expected at least 1 positional argument, '
                            'got %d' % (len(args)-1))

_exit_wrapper = self._create_cb_wrapper(callback, *args, **kwds)

# We changed the signature, so using @wraps is not appropriate, but
        # setting __wrapped__ may still help with introspection.
        _exit_wrapper.__wrapped__ = callback
        self._push_exit_callback(_exit_wrapper)
        return callback  # Allow use as a decorator
    callback.__text_signature__ = '($self, callback, /, *args, **kwds)'

def _push_cm_exit(self, cm, cm_exit):
        """Helper to correctly register callbacks to __exit__ methods."""
        _exit_wrapper = self._create_exit_wrapper(cm, cm_exit)
        self._push_exit_callback(_exit_wrapper, True)

def _push_exit_callback(self, callback, is_sync=True):
        self._exit_callbacks.append((is_sync, callback))

# Inspired by discussions on http://bugs.python.org/issue13585
class ExitStack(_BaseExitStack, AbstractContextManager):
    """Context manager for dynamic management of a stack of exit callbacks.

For example:
        with ExitStack() as stack:
            files = [stack.enter_context(open(fname)) for fname in filenames]
            # All opened files will automatically be closed at the end of
            # the with statement, even if attempts to open files later
            # in the list raise an exception.
    """

def __enter__(self):
        return self

def __exit__(self, *exc_details):
        received_exc = exc_details[0] is not None

# We manipulate the exception state so it behaves as though
        # we were actually nesting multiple with statements
        frame_exc = sys.exc_info()[1]
        def _fix_exception_context(new_exc, old_exc):
            # Context may not be correct, so find the end of the chain
            while 1:
                exc_context = new_exc.__context__
                if exc_context is old_exc:
                    # Context is already set correctly (see issue 20317)
                    return
                if exc_context is None or exc_context is frame_exc:
                    break
                new_exc = exc_context
            # Change the end of the chain to point to the exception
            # we expect it to reference
            new_exc.__context__ = old_exc

# Callbacks are invoked in LIFO order to match the behaviour of
        # nested context managers
        suppressed_exc = False
        pending_raise = False
        while self._exit_callbacks:
            is_sync, cb = self._exit_callbacks.pop()
            assert is_sync
            try:
                if cb(*exc_details):
                    suppressed_exc = True
                    pending_raise = False
                    exc_details = (None, None, None)
            except:
                new_exc_details = sys.exc_info()
                # simulate the stack of exceptions by setting the context
                _fix_exception_context(new_exc_details[1], exc_details[1])
                pending_raise = True
                exc_details = new_exc_details
        if pending_raise:
            try:
                # bare "raise exc_details[1]" replaces our carefully
                # set-up context
                fixed_ctx = exc_details[1].__context__
                raise exc_details[1]
            except BaseException:
                exc_details[1].__context__ = fixed_ctx
                raise
        return received_exc and suppressed_exc

def close(self):
        """Immediately unwind the context stack."""
        self.__exit__(None, None, None)

# Inspired by discussions on https://bugs.python.org/issue29302
class AsyncExitStack(_BaseExitStack, AbstractAsyncContextManager):
    """Async context manager for dynamic management of a stack of exit
    callbacks.

For example:
        async with AsyncExitStack() as stack:
            connections = [await stack.enter_async_context(get_connection())
                for i in range(5)]
            # All opened connections will automatically be released at the
            # end of the async with statement, even if attempts to open a
            # connection later in the list raise an exception.
    """

@staticmethod
    def _create_async_exit_wrapper(cm, cm_exit):
        return MethodType(cm_exit, cm)

@staticmethod
    def _create_async_cb_wrapper(callback, /, *args, **kwds):
        async def _exit_wrapper(exc_type, exc, tb):
            await callback(*args, **kwds)
        return _exit_wrapper

async def enter_async_context(self, cm):
        """Enters the supplied async context manager.

If successful, also pushes its __aexit__ method as a callback and
        returns the result of the __aenter__ method.
        """
        _cm_type = type(cm)
        _exit = _cm_type.__aexit__
        result = await _cm_type.__aenter__(cm)
        self._push_async_cm_exit(cm, _exit)
        return result

def push_async_exit(self, exit):
        """Registers a coroutine function with the standard __aexit__ method
        signature.

Can suppress exceptions the same way __aexit__ method can.
        Also accepts any object with an __aexit__ method (registering a call
        to the method instead of the object itself).
        """
        _cb_type = type(exit)
        try:
            exit_method = _cb_type.__aexit__
        except AttributeError:
            # Not an async context manager, so assume it's a coroutine function
            self._push_exit_callback(exit, False)
        else:
            self._push_async_cm_exit(exit, exit_method)
        return exit  # Allow use as a decorator

def push_async_callback(*args, **kwds):
        """Registers an arbitrary coroutine function and arguments.

Cannot suppress exceptions.
        """
        if len(args) >= 2:
            self, callback, *args = args
        elif not args:
            raise TypeError("descriptor 'push_async_callback' of "
                            "'AsyncExitStack' object needs an argument")
        elif 'callback' in kwds:
            callback = kwds.pop('callback')
            self, *args = args
            import warnings
            warnings.warn("Passing 'callback' as keyword argument is deprecated",
                          DeprecationWarning, stacklevel=2)
        else:
            raise TypeError('push_async_callback expected at least 1 '
                            'positional argument, got %d' % (len(args)-1))

_exit_wrapper = self._create_async_cb_wrapper(callback, *args, **kwds)

# We changed the signature, so using @wraps is not appropriate, but
        # setting __wrapped__ may still help with introspection.
        _exit_wrapper.__wrapped__ = callback
        self._push_exit_callback(_exit_wrapper, False)
        return callback  # Allow use as a decorator
    push_async_callback.__text_signature__ = '($self, callback, /, *args, **kwds)'

async def aclose(self):
        """Immediately unwind the context stack."""
        await self.__aexit__(None, None, None)

def _push_async_cm_exit(self, cm, cm_exit):
        """Helper to correctly register coroutine function to __aexit__
        method."""
        _exit_wrapper = self._create_async_exit_wrapper(cm, cm_exit)
        self._push_exit_callback(_exit_wrapper, False)

async def __aenter__(self):
        return self

async def __aexit__(self, *exc_details):
        received_exc = exc_details[0] is not None

if cb_suppress:
                    suppressed_exc = True
                    pending_raise = False
                    exc_details = (None, None, None)
            except:
                new_exc_details = sys.exc_info()
                # simulate the stack of exceptions by setting the context
                _fix_exception_context(new_exc_details[1], exc_details[1])
                pending_raise = True
                exc_details = new_exc_details
        if pending_raise:
            try:
                # bare "raise exc_details[1]" replaces our carefully
                # set-up context
                fixed_ctx = exc_details[1].__context__
                raise exc_details[1]
            except BaseException:
                exc_details[1].__context__ = fixed_ctx
                raise
        return received_exc and suppressed_exc

class nullcontext(AbstractContextManager):
    """Context manager that does no additional processing.

Used as a stand-in for a normal context manager, when a particular
    block of code is only sometimes used with a normal context manager:

cm = optional_cm if condition else nullcontext()
    with cm:
        # Perform operation, using optional_cm if condition is True
    """

def __init__(self, enter_result=None):
        self.enter_result = enter_result

def __enter__(self):
        return self.enter_result

def __exit__(self, *excinfo):
        pass

cmd: