Mailman 3 January 2020 - Python-Dev

PEP 458: Secure PyPI downloads with package signing
by Sumana Harihareswara 12 Feb '20

12 Feb '20

Hi! I'm forwarding this on behalf of Marina Moore https://github.com/mnm678 . - Sumana Harihareswara --- PEP 458 ( https://www.python.org/dev/peps/pep-0458/ ) proposes using The Update Framework (TUF) to allow users of PyPI to verify that the packages they install originate from PyPI. Implementing this PEP would provide protection in the event of an attack on PyPI, its mirrors, or the network used to install packages. We started this PEP in 2013, and have recently revised it and restarted discussion. Recent discussion and revision of the PEP has been taking place on Discourse ( https://discuss.python.org/t/pep-458-secure-pypi-downloads-with-package-sig… ). The PEP is ready for review and I look forward to your feedback! Thanks, Marina Moore PEP 458 coauthor

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extern "C" { ... } in Include/cpython/*.h
by Skip Montanaro 08 Feb '20

08 Feb '20

(Apologies. Not sure where to ask this, and I'm not much of a C++ programmer. Maybe I should have just added a comment to the still-open issue.) I just noticed that Nick migrated the guts of Include/frameobject.h to include/cpython/frameobject.h. It's not clear to me that the latter should be #include'd directly from anywhere other than Include/frameobject.h. If that's the case, does the extern "C" stuff still need to be replicated in the lower level file? Won't the scope of the extern "C" block in Include/frameobject.h be active at the lower level? Whatever the correct answer is, I suspect the same constraints should apply to all Include/cpython/*.h files. Skip

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Maintenance of multiprocessing module: there are a few stalled issues/patches
by mailer＠app.tempr.email 31 Jan '20

31 Jan '20

Couldn't help but notice that there are quite a few stalled issues/patches, some of them for years even. :-/ So I thought, it might help to bump them here on the mailing list. https://bugs.python.org/issue28053https://github.com/python/cpython/pull/99…

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Summary of Python tracker Issues
by Python tracker 31 Jan '20

31 Jan '20

ACTIVITY SUMMARY (2020-01-24 - 2020-01-31) Python tracker at https://bugs.python.org/ To view or respond to any of the issues listed below, click on the issue. Do NOT respond to this message. Issues counts and deltas: open 7300 (+15) closed 43962 (+52) total 51262 (+67) Open issues with patches: 2858 Issues opened (56) ================== #36051: Drop the GIL during large bytes.join operations? https://bugs.python.org/issue36051 reopened by skip.montanaro #39350: Remove deprecated fractions.gcd() https://bugs.python.org/issue39350 reopened by mark.dickinson #39391: Nondeterministic Pydoc output on functions that have functions https://bugs.python.org/issue39391 reopened by peteroupc #39435: pickle: inconsistent arguments pickle.py vs _pickle.c vs docs https://bugs.python.org/issue39435 reopened by pitrou #39445: h5py not playing nicely with subprocess and mpirun https://bugs.python.org/issue39445 opened by Rafael Laboissière #39447: imaplib documentation claims that commands return a string, bu https://bugs.python.org/issue39447 opened by dkg #39448: Add regen-frozen makefile target https://bugs.python.org/issue39448 opened by nascheme #39450: unittest TestCase shortDescription does not strip whitespace https://bugs.python.org/issue39450 opened by scirelli #39451: enum.Enum reference count leaks https://bugs.python.org/issue39451 opened by dan.gass(a)gmail.com #39452: Improve the __main__ module documentation https://bugs.python.org/issue39452 opened by maggyero #39453: Use-after-free in list contain https://bugs.python.org/issue39453 opened by corona10 #39454: when \\u in byte_string ,byte_string.decode('raw_unicode_escap https://bugs.python.org/issue39454 opened by yayiba1223 #39456: Make IDLE calltip tests work when there are no docstrings https://bugs.python.org/issue39456 opened by terry.reedy #39457: Add an autocommit property to sqlite3.Connection with a PEP 24 https://bugs.python.org/issue39457 opened by maggyero #39460: test_zipfile: test_add_file_after_2107() sometimes fails on Fe https://bugs.python.org/issue39460 opened by vstinner #39461: [RFE] os.environ should support Path-like values, like subproc https://bugs.python.org/issue39461 opened by Antony.Lee #39462: DataClass typo-unsafe attribute creation & unexpected behaviou https://bugs.python.org/issue39462 opened by marcelpvisser #39463: ast.Constant, bytes, and ast.unparse https://bugs.python.org/issue39463 opened by Tal Ben-Nun #39464: Allow translating argparse error messages https://bugs.python.org/issue39464 opened by DjMorgul #39465: Design a subinterpreter friendly alternative to _Py_IDENTIFIER https://bugs.python.org/issue39465 opened by ncoghlan #39467: Allow to deprecate CLI arguments in argparse https://bugs.python.org/issue39467 opened by 4383 #39468: Improved the site module's permission handling while writing . https://bugs.python.org/issue39468 opened by opensource-assist #39469: Support for relative home path in pyvenv.cfg https://bugs.python.org/issue39469 opened by Jeff.Edwards #39470: Indicate that os.makedirs is equivalent to Path.mkdir https://bugs.python.org/issue39470 opened by nanjekyejoannah #39471: Meaning and clarification of PyBuffer_Release() https://bugs.python.org/issue39471 opened by seberg #39472: IDLE: improve handling of int entry in settings dialog https://bugs.python.org/issue39472 opened by terry.reedy #39473: Enable import behavior consistency option https://bugs.python.org/issue39473 opened by bluelantern #39474: col_offset for parenthesized expressions looks weird https://bugs.python.org/issue39474 opened by BTaskaya #39475: window.getmaxyx() doesn't return updated height when window is https://bugs.python.org/issue39475 opened by nova #39477: multiprocessing Pool maxtasksperchild=0 raises exception with https://bugs.python.org/issue39477 opened by jeyekomon #39479: [RFE] Add math.lcm() function: Least Common Multiple https://bugs.python.org/issue39479 opened by Ananthakrishnan #39480: referendum reference is needlessly annoying https://bugs.python.org/issue39480 opened by diziet #39481: Implement PEP 585 (Type Hinting Generics In Standard Collectio https://bugs.python.org/issue39481 opened by gvanrossum #39482: Write 2to3 fixer for collections.abc imports https://bugs.python.org/issue39482 opened by opoplawski #39483: Proposial add loop parametr to run in asyncio https://bugs.python.org/issue39483 opened by heckad #39484: time_ns() and time() cannot be compared on windows https://bugs.python.org/issue39484 opened by vxgmichel #39486: bug in %-formatting in Python, related to escaped %-characters https://bugs.python.org/issue39486 opened by Carl.Friedrich.Bolz #39488: test_largefile: TestSocketSendfile.test_it() uses too much dis https://bugs.python.org/issue39488 opened by vstinner #39489: Remove COUNT_ALLOCS special build https://bugs.python.org/issue39489 opened by vstinner #39490: Python Uninstaller fails to clean up the old path variables wh https://bugs.python.org/issue39490 opened by brucelong #39491: Import PEP 593 (Flexible function and variable annotations) su https://bugs.python.org/issue39491 opened by jstasiak #39492: reference cycle affecting Pickler instances (Python3.8+) https://bugs.python.org/issue39492 opened by pierreglaser #39495: xml.etree.ElementTree.TreeBuilder.start differs between pure P https://bugs.python.org/issue39495 opened by hauntsaninja #39496: Inelegant loops in Modules/_sqlite/cursor.c https://bugs.python.org/issue39496 opened by alex.henrie #39498: Signpost security considerations in library https://bugs.python.org/issue39498 opened by anthonypjshaw #39500: Document PyUnicode_IsIdentifier() function https://bugs.python.org/issue39500 opened by vstinner #39501: gettext's default localedir does not match documentation https://bugs.python.org/issue39501 opened by moht #39502: test_zipfile fails on AIX due to time.localtime https://bugs.python.org/issue39502 opened by EGuesnet #39503: [security][CVE-2020-8492] Denial of service in urllib.request. https://bugs.python.org/issue39503 opened by vstinner #39504: inspect.signature throws RuntimeError on select.epoll.register https://bugs.python.org/issue39504 opened by hauntsaninja #39505: redundant ‘/’ in $env:VIRTUAL_ENV when use venv in powersh https://bugs.python.org/issue39505 opened by Schwarzichet #39507: http library missing HTTP status code 418 "I'm a teapot" https://bugs.python.org/issue39507 opened by trrhodes #39508: no module curses error although i downloaded the module - wind https://bugs.python.org/issue39508 opened by haim986 #39509: Update HTTP status code to follow IANA https://bugs.python.org/issue39509 opened by corona10 #39510: use-after-free in BufferedReader.readinto() https://bugs.python.org/issue39510 opened by phg #39511: [subinterpreters] Per-interpreter singletons (None, True, Fals https://bugs.python.org/issue39511 opened by vstinner Most recent 15 issues with no replies (15) ========================================== #39510: use-after-free in BufferedReader.readinto() https://bugs.python.org/issue39510 #39508: no module curses error although i downloaded the module - wind https://bugs.python.org/issue39508 #39505: redundant ‘/’ in $env:VIRTUAL_ENV when use venv in powersh https://bugs.python.org/issue39505 #39504: inspect.signature throws RuntimeError on select.epoll.register https://bugs.python.org/issue39504 #39501: gettext's default localedir does not match documentation https://bugs.python.org/issue39501 #39498: Signpost security considerations in library https://bugs.python.org/issue39498 #39496: Inelegant loops in Modules/_sqlite/cursor.c https://bugs.python.org/issue39496 #39492: reference cycle affecting Pickler instances (Python3.8+) https://bugs.python.org/issue39492 #39491: Import PEP 593 (Flexible function and variable annotations) su https://bugs.python.org/issue39491 #39490: Python Uninstaller fails to clean up the old path variables wh https://bugs.python.org/issue39490 #39488: test_largefile: TestSocketSendfile.test_it() uses too much dis https://bugs.python.org/issue39488 #39482: Write 2to3 fixer for collections.abc imports https://bugs.python.org/issue39482 #39481: Implement PEP 585 (Type Hinting Generics In Standard Collectio https://bugs.python.org/issue39481 #39477: multiprocessing Pool maxtasksperchild=0 raises exception with https://bugs.python.org/issue39477 #39475: window.getmaxyx() doesn't return updated height when window is https://bugs.python.org/issue39475 Most recent 15 issues waiting for review (15) ============================================= #39511: [subinterpreters] Per-interpreter singletons (None, True, Fals https://bugs.python.org/issue39511 #39510: use-after-free in BufferedReader.readinto() https://bugs.python.org/issue39510 #39509: Update HTTP status code to follow IANA https://bugs.python.org/issue39509 #39507: http library missing HTTP status code 418 "I'm a teapot" https://bugs.python.org/issue39507 #39505: redundant ‘/’ in $env:VIRTUAL_ENV when use venv in powersh https://bugs.python.org/issue39505 #39503: [security][CVE-2020-8492] Denial of service in urllib.request. https://bugs.python.org/issue39503 #39502: test_zipfile fails on AIX due to time.localtime https://bugs.python.org/issue39502 #39500: Document PyUnicode_IsIdentifier() function https://bugs.python.org/issue39500 #39498: Signpost security considerations in library https://bugs.python.org/issue39498 #39496: Inelegant loops in Modules/_sqlite/cursor.c https://bugs.python.org/issue39496 #39495: xml.etree.ElementTree.TreeBuilder.start differs between pure P https://bugs.python.org/issue39495 #39492: reference cycle affecting Pickler instances (Python3.8+) https://bugs.python.org/issue39492 #39491: Import PEP 593 (Flexible function and variable annotations) su https://bugs.python.org/issue39491 #39489: Remove COUNT_ALLOCS special build https://bugs.python.org/issue39489 #39488: test_largefile: TestSocketSendfile.test_it() uses too much dis https://bugs.python.org/issue39488 Top 10 most discussed issues (10) ================================= #39460: test_zipfile: test_add_file_after_2107() sometimes fails on Fe https://bugs.python.org/issue39460 36 msgs #39479: [RFE] Add math.lcm() function: Least Common Multiple https://bugs.python.org/issue39479 22 msgs #39461: [RFE] os.environ should support Path-like values, like subproc https://bugs.python.org/issue39461 18 msgs #39502: test_zipfile fails on AIX due to time.localtime https://bugs.python.org/issue39502 14 msgs #39489: Remove COUNT_ALLOCS special build https://bugs.python.org/issue39489 9 msgs #39430: tarfile.open(mode="r") race condition when importing lzma https://bugs.python.org/issue39430 8 msgs #39483: Proposial add loop parametr to run in asyncio https://bugs.python.org/issue39483 7 msgs #18233: SSLSocket.getpeercertchain() https://bugs.python.org/issue18233 5 msgs #38792: IDLE calltips may not properly close on KeyboardInterrupt https://bugs.python.org/issue38792 5 msgs #39380: ftplib uses latin-1 as default encoding https://bugs.python.org/issue39380 5 msgs Issues closed (50) ================== #11549: Build-out an AST optimizer, moving some functionality out of t https://bugs.python.org/issue11549 closed by rhettinger #13306: Add diagnostic tools to importlib? https://bugs.python.org/issue13306 closed by brett.cannon #14715: test.support.DirsOnSysPath should be replaced by importlib.tes https://bugs.python.org/issue14715 closed by eric.smith #15243: Misleading documentation for __prepare__ https://bugs.python.org/issue15243 closed by berker.peksag #24928: mock.patch.dict spoils order of items in collections.OrderedDi https://bugs.python.org/issue24928 closed by rhettinger #25597: unittest.mock does not wrap dunder methods (__getitem__ etc) https://bugs.python.org/issue25597 closed by xtreak #30780: IDLE: configdialog - add tests for ConfigDialog GUI. https://bugs.python.org/issue30780 closed by terry.reedy #31414: IDLE: Entry tests should delete before insert. https://bugs.python.org/issue31414 closed by terry.reedy #33339: Using default encoding with `subprocess.run()` is not obvious https://bugs.python.org/issue33339 closed by eryksun #34095: [2.7] Seg fault on archlinux 32 when run tests with xvfb-run https://bugs.python.org/issue34095 closed by benjamin.peterson #36350: inspect.Signature.parameters and inspect.BoundArguments.argume https://bugs.python.org/issue36350 closed by inada.naoki #36654: Add example to tokenize.tokenize https://bugs.python.org/issue36654 closed by berker.peksag #37955: mock.patch incorrect reference to Mock https://bugs.python.org/issue37955 closed by cjw296 #38350: ./configure --with-pydebug should use -O0 rather than -Og https://bugs.python.org/issue38350 closed by vstinner #38473: AttributeError on asserting autospecced mock object added usin https://bugs.python.org/issue38473 closed by xtreak #38631: Replace Py_FatalError() with regular Python exceptions https://bugs.python.org/issue38631 closed by vstinner #38797: x86-64 High Sierra 3.x buildbot worker fails to build Python: https://bugs.python.org/issue38797 closed by vstinner #38883: Path.home() should ignore HOME env var like os.path.expanduser https://bugs.python.org/issue38883 closed by steve.dower #38932: unittest.mock.Mock.reset_mocks does not pass all arguments to https://bugs.python.org/issue38932 closed by cjw296 #39082: AsyncMock is unable to correctly patch static or class methods https://bugs.python.org/issue39082 closed by cjw296 #39153: Clarify refcounting semantics of PyDict_SetItem[String] https://bugs.python.org/issue39153 closed by corona10 #39165: Completeness and symmetry in RE, avoid `findall(...)[0]` https://bugs.python.org/issue39165 closed by rhettinger #39248: test_distutils fails on PPC64 Fedora 3.x: /tmp/subprocess.py https://bugs.python.org/issue39248 closed by vstinner #39287: Document UTF-8 mode in the using/windows. https://bugs.python.org/issue39287 closed by inada.naoki #39309: Please delete my account https://bugs.python.org/issue39309 closed by berker.peksag #39374: Key in sort -> Callable Object instead of function https://bugs.python.org/issue39374 closed by rhettinger #39388: IDLE: Changes to keybindings aren't reverted on cancel https://bugs.python.org/issue39388 closed by terry.reedy #39390: shutil.copytree - 3.8 changed argument types of the ignore cal https://bugs.python.org/issue39390 closed by giampaolo.rodola #39392: Python Turtle is not filling alternate overlapping areas of a https://bugs.python.org/issue39392 closed by terry.reedy #39393: Misleading error message upon dependent DLL resolution failure https://bugs.python.org/issue39393 closed by steve.dower #39401: [CVE-2020-8315] Unsafe dll loading in getpathp.c on Win7 https://bugs.python.org/issue39401 closed by ned.deily #39424: [easy] test_signal: test_pidfd_send_signal() uses deprecated a https://bugs.python.org/issue39424 closed by serhiy.storchaka #39434: Remove unnecessary logic of float __floordiv__ https://bugs.python.org/issue39434 closed by mark.dickinson #39443: Inhomogeneous behaviour for descriptors in between the class-i https://bugs.python.org/issue39443 closed by rhettinger #39444: Incorrect description of sorting for PrettyPrinter https://bugs.python.org/issue39444 closed by steven.daprano #39446: Documentation should reflect that all dicts are now ordered https://bugs.python.org/issue39446 closed by rhettinger #39449: New Assignment operator https://bugs.python.org/issue39449 closed by SilentGhost #39455: Update the documentation for the linecache module https://bugs.python.org/issue39455 closed by opensource-assist #39458: Multiprocessing.Pool maxtasksperchild=1 doesn't work https://bugs.python.org/issue39458 closed by Gabriel Tardif #39459: test_import: test_unwritable_module() fails on AMD64 Fedora St https://bugs.python.org/issue39459 closed by dino.viehland #39466: Spam https://bugs.python.org/issue39466 closed by xtreak #39476: Not convinced with the dynamic data type assignment https://bugs.python.org/issue39476 closed by steven.daprano #39478: can we add a median function https://bugs.python.org/issue39478 closed by vstinner #39485: Bug in mock running on PyPy3 https://bugs.python.org/issue39485 closed by cjw296 #39487: Merge duplicated _Py_IDENTIFIER identifiers in C code https://bugs.python.org/issue39487 closed by ncoghlan #39493: typing.py has an incorrect definition of closed https://bugs.python.org/issue39493 closed by gvanrossum #39494: Extra null terminators in keyword arrays in sqlite module https://bugs.python.org/issue39494 closed by berker.peksag #39497: Unused variable script_str in pysqlite_cursor_executescript https://bugs.python.org/issue39497 closed by berker.peksag #39499: ValueError using index on tuple is not showing the tuple value https://bugs.python.org/issue39499 closed by xtreak #39506: operator |= on sets does not behave like the update method https://bugs.python.org/issue39506 closed by ammar2

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Limited API, MetaClasses, and ExtensionMetaClasses
by Sebastian Berg 31 Jan '20

31 Jan '20

Hi all, I may be thinking in the wrong direction, but right now `PyType_Type.tp_new` will resolves the `metaclass` from the bases and call: type = (PyTypeObject *)metatype->tp_alloc(metatype, nslots); where `metatype` is actually resolved from the metatype of the bases. In contrast `PyType_FromSpecWithBases` immediately calls: res = (PyHeapTypeObject*)PyType_GenericAlloc(&PyType_Type, 0); So I am curious whether `PyType_FromSpecWithBases` should not do the same thing, or as to why it does not? I would also assume that it actually fails to inherit a possible MetaClass completely, but I have not checked that. That is the first question. The second, more important one, is whether ExtensionMetaClasses are a thing at all? Is it reasonable to explore them, or should I rather give up and use something more like ABCMeta, which stores information in the `HeapType->tp_dict`, plus tag on information to the actual instances as needed? Right now it seems completely fine to me, except that the creation itself is complicated (and a confusing, but its MetaClasses...). I am exploring this for NumPy. PySIDE is using such things and wrangled it into the limited API [1] (PySIDE needs to store a QT pointer additionally). When I looked the code, I was fairly sure that this only happened to work because Python allocates a slightly larger space (effectively making it `nslots+1`, or 1 above). As far as I can see, the only thing that happens if I use such an ExtensionMetaClass is that I have a HeapType with a different tp_basicsize. And I do not see why that should be any different than a normal Python object. Best, Sebastian [1] https://github.com/pyside/pyside2-setup/blob/5.11/sources/shiboken2/libshib…

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PEP 613 Accepted
by Barry Warsaw 30 Jan '20

30 Jan '20

The Steering Council has considered Guido’s request for pronouncement on PEP 613 - Explicit Type Aliases, written by Shannon Zhu and sponsored by Guido van Rossum. The Council unanimously accepts PEP 613. Congratulations! We’ll leave it to the sponsor and author to update the PEP accordingly. -Barry (on behalf of the Python Steering Council)

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Static inline functions in header files, limited API and the stable ABI
by Victor Stinner 30 Jan '20

30 Jan '20

Hi, Is it ok to add a static inline function to the limited API? Can it cause ABI issue? Or is it safer to add a regular function? For example, is it safe to add the following function to the limited API? static inline PyObject * _PyObject_CallOneArg(PyObject *func, PyObject *arg) { ... return _PyObject_VectorcallTstate(tstate, func, args, nargsf, NULL); } Or should it be an opaque definition like the following function? PyAPI_FUNC(PyObject *) PyObject_CallNoArgs(PyObject *func); I came to this question while reviewing "Make Vectorcall public" C API: https://bugs.python.org/issue39245 https://github.com/python/cpython/pull/17893 Victor -- Night gathers, and now my watch begins. It shall not end until my death.

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Remove COUNT_ALLOCS special build
by Victor Stinner 29 Jan '20

29 Jan '20

Hi, I would like to confirm that there is no user of the Python "COUNT_ALLOCS" special build, because I plan to remove it from Python 3.9. If you use it, please raise your hand and explain why other debug tools don't fit your specific use case. -- I'm always annoyed by "#ifdef COUNT_ALLOCS" code which is common in code related to reference counting (object.h, object.c, typeobject.c). It makes the code harder to read and harder to maintain. It's a 27 years old feature which always required to rebuild Python with COUNT_ALLOCS macro defined. In clear, you have to know about the feature and build your own Python binary to use it. COUNT_ALLOCS was used for 6 years (2010-2015) in the debug build of Python of the Fedora package. Sadly, C extensions provided by Fedora are only built in release mode, and so cannot be used by the debug build. python2.7-debug requires to rebuild all C extensions in debug mode. IMHO nobody ever used python2.7-debug to debug real applications. The feature was added to Fedora debug build by Dave Malcolm in 2010 to help him to debug memory leaks. Later, he wrote: "I don't think this patch ever really bought us much, and it sounds like there are better tools for this now, so feel free to drop the COUNT_ALLOC patches." So the feature was dropped from Python 3 package in 2015. I never ever used this feature. I consider that there are now way better tools to debug memory leaks in Python 3, like tracemalloc and multiple tools based on gc.get_objects(). I failed to find any user of COUNT_ALLOCS on the Internet. I'm quite sure that many core developers never heard about this special build. I proposed https://bugs.python.org/issue39489 and https://github.com/python/cpython/pull/18259 to remove the feature. My PR basically only removes code: 34 files changed, 24 insertions(+), 470 deletions(-) Do you see any reason to keep COUNT_ALLOCS in Python 3.9? If yes, please elaborate :-) Victor -- Night gathers, and now my watch begins. It shall not end until my death.

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Question: how to extend standard Python library to add new functionalities?
by daniel.wangksu＠gmail.com 29 Jan '20

29 Jan '20

Hi all, I want to add openssl engine in Python SSL library. I know that if the new functions can be added in Python we can inherit existing class (such as ssl). However, It seems the SSL module extends _SSL module which is written in C. I'm not sure how can I extend SSL module in this situation. Any help would be deeply appreciated!

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Typo in Link
by onlinejudge95 28 Jan '20

28 Jan '20

Hi team, First of all is it a right place to ask this question? If not i would love to redirect and apologise for any inconvenience. While i was going through the wiki.python.org links, i saw that the urls( https://wiki.python.org/moin) contains *moin*, is it expected? Thanks, onlinejudge95

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