Mailman 3 January 2020 - Python-Dev

Requesting PR review on locale module
by Cédric Krier 11 Jan '20

11 Jan '20

Hi, Few months ago, I submitted a PR [1] for the bpo [2] about locale.format casting Decimal into float. Has someone some times to finish the review? This change is blocking a bugfix on Tryton [3]. [1] https://github.com/python/cpython/pull/15275 [2] https://bugs.python.org/issue34311 [3] https://bugs.tryton.org/issue8574 Thanks, -- Cédric Krier - B2CK SPRL Email/Jabber: cedric.krier(a)b2ck.com Tel: +32 472 54 46 59 Website: http://www.b2ck.com/

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Is anyone aware of any existing tests for ternary_op in abstract.c?
by Nick Coghlan 11 Jan '20

11 Jan '20

[Note: I don't think this is a high priority issue, as it only relates to doing mixed-type modular exponentiation, and that seems like an inherently bad idea anyway. But I'm also curious if anyone is able to explain the current behaviour, as I haven't come up with a better explanation than "It doesn't actually work, but nobody needs it enough to complain about it not working"] While writing up bpo-39302 [1], I tried experimenting at the REPL to see if I could get __pow__ to ever exercise the code paths where 3-argument pow() is handled by the exponent or the modulus (as described in the source code and PEP 208), rather than the usual case where it is handled by the base. I failed - the only time I could get my custom __pow__ implementation to run was when it was the base, never when it was the modulus or exponent. This means that, as far as I'm able to tell, ternary_op in abstract.c isn't actually working as intended, or at least, it doesn't work in combination with the way the `nb_power` slot wrapper is implemented in typeobject.c. That slot wrapper only ever calls the Python level function provided by the first operand, even though ternary_op calls 3 different slot implementations, they all ultimately get resolved as attempts to call the same python level function (the `__pow__` implementation on the base). I couldn't find any test cases that exercise this functionality, so even though PEP 208 describes the expected semantics, it isn't clear whether or not the implementation has ever achieved them. This is the session where I tried to see if I could get it to work the way I expected it to work based on the comments in ternary_op: [py3.7]> class _PowArgsMixin: ... def __pow__(*args): ... return tuple(map(type, args)) ... [py3.7]> class NoPow: ... pass ... [py3.7]> class NotImplementedPow: ... def __pow__(*args): ... return NotImplemented ... [py3.7]> class UnrelatedPow(_PowArgsMixin): ... pass ... [py3.7]> class ChildOfNoPow(_PowArgsMixin, NoPow): ... pass ... [py3.7]> class ChildOfNotImplementedPow(_PowArgsMixin, NotImplementedPow): ... pass ... [py3.7]> no_pow = NoPow() [py3.7]> ni_pow = NotImplementedPow() [py3.7]> has_pow = UnrelatedPow() [py3.7]> child_no = ChildOfNoPow() [py3.7]> child_ni = ChildOfNotImplementedPow() [py3.7]> # They all give the expected result as the base ... pow(has_pow, no_pow, no_pow) (<class '__main__.UnrelatedPow'>, <class '__main__.NoPow'>, <class '__main__.NoPow'>) [py3.7]> pow(has_pow, ni_pow, ni_pow) (<class '__main__.UnrelatedPow'>, <class '__main__.NotImplementedPow'>, <class '__main__.NotImplementedPow'>) [py3.7]> pow(child_no, no_pow, no_pow) (<class '__main__.ChildOfNoPow'>, <class '__main__.NoPow'>, <class '__main__.NoPow'>) [py3.7]> pow(child_ni, ni_pow, ni_pow) (<class '__main__.ChildOfNotImplementedPow'>, <class '__main__.NotImplementedPow'>, <class '__main__.NotImplementedPow'>) [py3.7]> # But none of them work when given as the exponent ... pow(no_pow, has_pow, no_pow) Traceback (most recent call last): File "<stdin>", line 2, in <module> TypeError: unsupported operand type(s) for pow(): 'NoPow', 'UnrelatedPow', 'NoPow' [py3.7]> pow(ni_pow, has_pow, ni_pow) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: unsupported operand type(s) for pow(): 'NotImplementedPow', 'UnrelatedPow', 'NotImplementedPow' [py3.7]> pow(no_pow, child_no, no_pow) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: unsupported operand type(s) for pow(): 'NoPow', 'ChildOfNoPow', 'NoPow' [py3.7]> pow(ni_pow, child_ni, ni_pow) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: unsupported operand type(s) for pow(): 'NotImplementedPow', 'ChildOfNotImplementedPow', 'NotImplementedPow' [py3.7]> # And none of them work when given as the modulus either ... pow(no_pow, no_pow, has_pow) Traceback (most recent call last): File "<stdin>", line 2, in <module> TypeError: unsupported operand type(s) for pow(): 'NoPow', 'NoPow', 'UnrelatedPow' [py3.7]> pow(ni_pow, ni_pow, has_pow) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: unsupported operand type(s) for pow(): 'NotImplementedPow', 'NotImplementedPow', 'UnrelatedPow' [py3.7]> pow(no_pow, no_pow, child_no) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: unsupported operand type(s) for pow(): 'NoPow', 'NoPow', 'ChildOfNoPow' [py3.7]> pow(ni_pow, ni_pow, child_ni) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: unsupported operand type(s) for pow(): 'NotImplementedPow', 'NotImplementedPow', 'ChildOfNotImplementedPow' [1] https://bugs.python.org/issue39302 -- Nick Coghlan | ncoghlan(a)gmail.com | Brisbane, Australia

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Summary of Python tracker Issues
by Python tracker 10 Jan '20

10 Jan '20

ACTIVITY SUMMARY (2020-01-03 - 2020-01-10) 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 7251 (+24) closed 43792 (+66) total 51043 (+90) Open issues with patches: 2846 Issues opened (63) ================== #25872: multithreading traceback KeyError when modifying file https://bugs.python.org/issue25872 reopened by xtreak #27657: urlparse fails if the path is numeric https://bugs.python.org/issue27657 reopened by orsenthil #29778: _Py_CheckPython3 uses uninitialized dllpath when embedder sets https://bugs.python.org/issue29778 reopened by vstinner #39158: ast.literal_eval() doesn't support empty sets https://bugs.python.org/issue39158 reopened by pablogsal #39204: Automate adding Type Annotations to Documentation https://bugs.python.org/issue39204 opened by cooperlees #39205: Hang when interpreter exits after ProcessPoolExecutor.shutdown https://bugs.python.org/issue39205 opened by bquinlan #39206: Modulefinder does not consider source file encoding https://bugs.python.org/issue39206 opened by Nicholas Feix #39207: concurrent.futures.ProcessPoolExecutor does not properly reap https://bugs.python.org/issue39207 opened by yus2047889 #39210: Sorting falls back to use __gt__ when __lt__ is not present https://bugs.python.org/issue39210 opened by yanmitrofanov #39212: Show qualified function name when giving arguments error https://bugs.python.org/issue39212 opened by cool-RR #39213: cmd should have a hook in the finally block of cmdloop https://bugs.python.org/issue39213 opened by Joseph Sible #39214: Add curses.window.in_wch https://bugs.python.org/issue39214 opened by Anthony Sottile #39217: GC of a ctypes object causes application crash https://bugs.python.org/issue39217 opened by Kevin Schlossser #39218: Assertion failure when calling statistics.variance() on a floa https://bugs.python.org/issue39218 opened by reed #39219: Fix attributes of syntax errors raized in the tokenizer https://bugs.python.org/issue39219 opened by serhiy.storchaka #39220: constant folding affects annotations despite 'from __future__ https://bugs.python.org/issue39220 opened by Carl.Friedrich.Bolz #39221: Cross compiled python installed wrong version of lib2to3/Gramm https://bugs.python.org/issue39221 opened by puchenyaka #39222: unittest.mock.Mock.parent is broken or undocumented https://bugs.python.org/issue39222 opened by florian.brucker #39224: HTTPConnection.timeout None support https://bugs.python.org/issue39224 opened by Daniel Farley #39228: traceback.FrameSummary does not handle exceptions from `repr() https://bugs.python.org/issue39228 opened by blueyed #39229: library/functions.rst causes translated builds to fail https://bugs.python.org/issue39229 opened by rffontenelle #39231: Mistaken notion in tutorial https://bugs.python.org/issue39231 opened by r0b #39232: asyncio crashes when tearing down the proactor event loop https://bugs.python.org/issue39232 opened by mikeshardmind #39233: glossary entry for parameter out-of-date for positional-only p https://bugs.python.org/issue39233 opened by mark.dickinson #39236: [venv] Adding a .gitignore file to virtual environments https://bugs.python.org/issue39236 opened by brett.cannon #39238: test_asyncio: test_cancel_make_subprocess_transport_exec() han https://bugs.python.org/issue39238 opened by vstinner #39241: Popen of python3.6 hangs on os.read(errpipe_read, 50000) https://bugs.python.org/issue39241 opened by liuxu1005 #39243: CDLL __init__ no longer supports name being passed as None whe https://bugs.python.org/issue39243 opened by David Heffernan #39244: multiprocessing.get_all_start_methods() wrong default on macOS https://bugs.python.org/issue39244 opened by stefanholek #39245: Public API for Vectorcall (PEP 590) https://bugs.python.org/issue39245 opened by petr.viktorin #39247: dataclass defaults and property don't work together https://bugs.python.org/issue39247 opened by Michael Robellard #39248: test_distutils fails on PPC64 Fedora 3.x: /tmp/subprocess.py https://bugs.python.org/issue39248 opened by vstinner #39249: difflib SequenceMatcher 200 char length limitation for ratio c https://bugs.python.org/issue39249 opened by Daniel Pezoa #39252: email.contentmanager.raw_data_manager bytes handler breaks on https://bugs.python.org/issue39252 opened by rmccampbell7 #39253: Running the test suite with --junit-xml and -R incorrectly rep https://bugs.python.org/issue39253 opened by pablogsal #39254: python shebang in python3 tarball files https://bugs.python.org/issue39254 opened by arekm #39257: contextvars.Context.run hangs forever in ProccessPoolExecutor https://bugs.python.org/issue39257 opened by ronserruya #39259: poplib.POP3/POP3_SSL should reject timeout = 0 (non-blocking m https://bugs.python.org/issue39259 opened by corona10 #39260: distutils.spawn: find_executable() Fails To Find Many Executab https://bugs.python.org/issue39260 opened by tbpassin #39263: Windows Installer can't select TargetDir in UI? https://bugs.python.org/issue39263 opened by Jameson Nash #39264: Fix UserDict.get to account for __missing__ https://bugs.python.org/issue39264 opened by bar.harel #39266: [2.7] test_bsddb3 leaked [1, 1, 1] file descriptors on AMD64 R https://bugs.python.org/issue39266 opened by vstinner #39267: Fix dict's __missing__ documentation https://bugs.python.org/issue39267 opened by bar.harel #39268: test_asyncio: test_create_server_ssl_verified() failed on AMD6 https://bugs.python.org/issue39268 opened by vstinner #39273: ncurses does not include BUTTON5_* constants https://bugs.python.org/issue39273 opened by michael.yoo(a)akunacapital.com #39274: Conversion from fractions.Fraction to bool https://bugs.python.org/issue39274 opened by francois-durand #39275: Traceback off by one line when https://bugs.python.org/issue39275 opened by facundobatista #39276: type() cause segmentation fault in callback function called f https://bugs.python.org/issue39276 opened by karczex #39277: _PyTime_FromDouble() fails to detect an integer overflow when https://bugs.python.org/issue39277 opened by graingert #39278: add docstrings to functions in pdb module https://bugs.python.org/issue39278 opened by carlbordum #39279: Don't allow non-Ascii digits in platform.py https://bugs.python.org/issue39279 opened by cool-RR #39280: Don't allow datetime parsing to accept non-Ascii digits https://bugs.python.org/issue39280 opened by cool-RR #39281: The CO_NESTED flag is associated with a significant performanc https://bugs.python.org/issue39281 opened by bup #39282: python-config --embed documentation https://bugs.python.org/issue39282 opened by M.Kerr #39283: Add ability to inherit unittest arguement parser https://bugs.python.org/issue39283 opened by atb00ker #39285: PurePath.match indicates case-sensitive nature and presents a https://bugs.python.org/issue39285 opened by xtreak #39286: Configure includes LIBS but does not pass it to distutils https://bugs.python.org/issue39286 opened by Alex Grund #39287: Document UTF-8 mode in the using/windows. https://bugs.python.org/issue39287 opened by inada.naoki #39288: Add math.nextafter(a, b) https://bugs.python.org/issue39288 opened by vstinner #39289: crypt.crypt fail with OSError "[Errno 22] Invalid argument" on https://bugs.python.org/issue39289 opened by vinay.sajip #39290: lib2to3.fixes.fix_import: support imports_as_name in traverse_ https://bugs.python.org/issue39290 opened by BTaskaya #39291: "pathlib.Path.link_to()" and "pathlib.Path.symlink_to()" have https://bugs.python.org/issue39291 opened by Rockmizu #39292: syslog constants behind rfc https://bugs.python.org/issue39292 opened by tryanunderwood(a)gmail.com Most recent 15 issues with no replies (15) ========================================== #39292: syslog constants behind rfc https://bugs.python.org/issue39292 #39291: "pathlib.Path.link_to()" and "pathlib.Path.symlink_to()" have https://bugs.python.org/issue39291 #39290: lib2to3.fixes.fix_import: support imports_as_name in traverse_ https://bugs.python.org/issue39290 #39288: Add math.nextafter(a, b) https://bugs.python.org/issue39288 #39287: Document UTF-8 mode in the using/windows. https://bugs.python.org/issue39287 #39286: Configure includes LIBS but does not pass it to distutils https://bugs.python.org/issue39286 #39285: PurePath.match indicates case-sensitive nature and presents a https://bugs.python.org/issue39285 #39282: python-config --embed documentation https://bugs.python.org/issue39282 #39281: The CO_NESTED flag is associated with a significant performanc https://bugs.python.org/issue39281 #39278: add docstrings to functions in pdb module https://bugs.python.org/issue39278 #39276: type() cause segmentation fault in callback function called f https://bugs.python.org/issue39276 #39273: ncurses does not include BUTTON5_* constants https://bugs.python.org/issue39273 #39268: test_asyncio: test_create_server_ssl_verified() failed on AMD6 https://bugs.python.org/issue39268 #39267: Fix dict's __missing__ documentation https://bugs.python.org/issue39267 #39266: [2.7] test_bsddb3 leaked [1, 1, 1] file descriptors on AMD64 R https://bugs.python.org/issue39266 Most recent 15 issues waiting for review (15) ============================================= #39290: lib2to3.fixes.fix_import: support imports_as_name in traverse_ https://bugs.python.org/issue39290 #39288: Add math.nextafter(a, b) https://bugs.python.org/issue39288 #39287: Document UTF-8 mode in the using/windows. https://bugs.python.org/issue39287 #39280: Don't allow datetime parsing to accept non-Ascii digits https://bugs.python.org/issue39280 #39279: Don't allow non-Ascii digits in platform.py https://bugs.python.org/issue39279 #39278: add docstrings to functions in pdb module https://bugs.python.org/issue39278 #39277: _PyTime_FromDouble() fails to detect an integer overflow when https://bugs.python.org/issue39277 #39267: Fix dict's __missing__ documentation https://bugs.python.org/issue39267 #39264: Fix UserDict.get to account for __missing__ https://bugs.python.org/issue39264 #39259: poplib.POP3/POP3_SSL should reject timeout = 0 (non-blocking m https://bugs.python.org/issue39259 #39245: Public API for Vectorcall (PEP 590) https://bugs.python.org/issue39245 #39233: glossary entry for parameter out-of-date for positional-only p https://bugs.python.org/issue39233 #39229: library/functions.rst causes translated builds to fail https://bugs.python.org/issue39229 #39228: traceback.FrameSummary does not handle exceptions from `repr() https://bugs.python.org/issue39228 #39224: HTTPConnection.timeout None support https://bugs.python.org/issue39224 Top 10 most discussed issues (10) ================================= #38623: Python documentation should mention how to find site-packages https://bugs.python.org/issue38623 12 msgs #29778: _Py_CheckPython3 uses uninitialized dllpath when embedder sets https://bugs.python.org/issue29778 9 msgs #39253: Running the test suite with --junit-xml and -R incorrectly rep https://bugs.python.org/issue39253 8 msgs #39029: TestMaildir.test_clean fails randomly under parallel tests https://bugs.python.org/issue39029 7 msgs #39158: ast.literal_eval() doesn't support empty sets https://bugs.python.org/issue39158 7 msgs #39280: Don't allow datetime parsing to accept non-Ascii digits https://bugs.python.org/issue39280 7 msgs #30717: Add unicode grapheme cluster break algorithm https://bugs.python.org/issue30717 6 msgs #39200: Fix inaccurate TypeError messages when calling with insufficie https://bugs.python.org/issue39200 6 msgs #39210: Sorting falls back to use __gt__ when __lt__ is not present https://bugs.python.org/issue39210 6 msgs #39243: CDLL __init__ no longer supports name being passed as None whe https://bugs.python.org/issue39243 6 msgs Issues closed (68) ================== #16806: col_offset is -1 and lineno is wrong for multiline string expr https://bugs.python.org/issue16806 closed by pablogsal #18930: os.spawnXX functions terminates process if second argument is https://bugs.python.org/issue18930 closed by pablogsal #18969: test suite: enable faulthandler timeout in assert_python https://bugs.python.org/issue18969 closed by vstinner #22606: Inconsistency between Python 2 and PyPy regarding future impor https://bugs.python.org/issue22606 closed by benjamin.peterson #23147: Possible error in _header_value_parser.py https://bugs.python.org/issue23147 closed by r.david.murray #24554: GC should happen when a subinterpreter is destroyed https://bugs.python.org/issue24554 closed by vstinner #24817: IDLE: disable format menu items when not applicable https://bugs.python.org/issue24817 closed by terry.reedy #28143: ASDL compatibility with Python 3 system interpreter https://bugs.python.org/issue28143 closed by cheryl.sabella #28367: Add more standard baud rate constants to "termios" https://bugs.python.org/issue28367 closed by twouters #28617: Why isn't "in" called a comparison operation? https://bugs.python.org/issue28617 closed by wim.glenn #31829: Portability issues with pickle https://bugs.python.org/issue31829 closed by cheryl.sabella #33095: Cross-reference isolated mode from relevant locations https://bugs.python.org/issue33095 closed by xtreak #33255: json.dumps has different behaviour if encoding='utf-8' or enco https://bugs.python.org/issue33255 closed by cheryl.sabella #34110: cPickle may raise AttributeError when loading concurrently in https://bugs.python.org/issue34110 closed by cheryl.sabella #34946: inspect.getcallargs is marked as deprecated in documentation, https://bugs.python.org/issue34946 closed by anthonypjshaw #35292: Make SimpleHTTPRequestHandler load mimetypes lazily https://bugs.python.org/issue35292 closed by steve.dower #36761: Extended slice assignment + iterable unpacking https://bugs.python.org/issue36761 closed by wim.glenn #37537: Compute allocated blocks in _Py_GetAllocatedBlocks() https://bugs.python.org/issue37537 closed by inada.naoki #38209: Simplify dataclasses.InitVar by using __class_getitem__() https://bugs.python.org/issue38209 closed by eric.smith #38502: regrtest: use process groups https://bugs.python.org/issue38502 closed by vstinner #38615: imaplib has no timeout setting https://bugs.python.org/issue38615 closed by vstinner #38871: lib2to3 generates invalid code with filter and ternary operato https://bugs.python.org/issue38871 closed by vstinner #38907: http.server (command) fails to bind dual-stack on Windows https://bugs.python.org/issue38907 closed by jaraco #38973: Shared Memory List Returns 0 Length https://bugs.python.org/issue38973 closed by HugeAckmen #39055: base64.b64decode() with validate=True does not raise for a tra https://bugs.python.org/issue39055 closed by serhiy.storchaka #39056: Issues with handling the -W option https://bugs.python.org/issue39056 closed by serhiy.storchaka #39057: Issues with urllib.request.proxy_bypass_environment https://bugs.python.org/issue39057 closed by serhiy.storchaka #39074: Threading memory leak in _shutdown_locks for non-daemon thread https://bugs.python.org/issue39074 closed by vstinner #39141: IDLE: system clear function returns 256 on Mac OS Catalina https://bugs.python.org/issue39141 closed by terry.reedy #39152: Faulty override of tkinter.Misc.configure in tkinter.ttk.Scale https://bugs.python.org/issue39152 closed by terry.reedy #39161: Py_NewInterpreter docs need updating for multi-phase initializ https://bugs.python.org/issue39161 closed by petr.viktorin #39166: Python 3.9.0a2 changed how "async for" traces its final iterat https://bugs.python.org/issue39166 closed by Mark.Shannon #39174: unicodedata.normalize failing with NFD and NFKD for some chara https://bugs.python.org/issue39174 closed by Lee Collins #39191: Coroutine is awaited despite an exception in run_until_complet https://bugs.python.org/issue39191 closed by asvetlov #39196: json fails to encode dictionary view types https://bugs.python.org/issue39196 closed by inada.naoki #39198: Lock may not be released in Logger.isEnabledFor https://bugs.python.org/issue39198 closed by vinay.sajip #39201: Threading.timer leaks memory in 3.8.0/3.8.1 https://bugs.python.org/issue39201 closed by vstinner #39203: python3 time module misses attributes in Mac installers https://bugs.python.org/issue39203 closed by ned.deily #39208: PDB pm function throws exception without sys import https://bugs.python.org/issue39208 closed by zach.ware #39209: Crash on REPL mode with long text copy and paste https://bugs.python.org/issue39209 closed by pablogsal #39211: Change in http.server default IP behavior? https://bugs.python.org/issue39211 closed by jaraco #39215: Type Annotation of nested function with positional only argume https://bugs.python.org/issue39215 closed by pablogsal #39216: ast_opt.c -- missing posonlyargs? https://bugs.python.org/issue39216 closed by pablogsal #39223: Fold constant slicing with slices https://bugs.python.org/issue39223 closed by serhiy.storchaka #39225: Python should warn when a global/local has the same name as a https://bugs.python.org/issue39225 closed by brett.cannon #39226: venv does not include pythonXX.lib https://bugs.python.org/issue39226 closed by Antonio Vázquez Blanco #39227: OverflowError in len(range(2**63)) https://bugs.python.org/issue39227 closed by rhettinger #39230: fail on datetime import if _datetime.py exists in PATH https://bugs.python.org/issue39230 closed by vstinner #39234: `enum.auto()` incrementation value not specified. https://bugs.python.org/issue39234 closed by eric.smith #39235: Generator expression has wrong line/col info when inside a Cal https://bugs.python.org/issue39235 closed by serhiy.storchaka #39237: Redundant call to round in delta_new https://bugs.python.org/issue39237 closed by vstinner #39239: select.epoll.unregister(fd) should not ignore EBADF https://bugs.python.org/issue39239 closed by vstinner #39240: keyerror in string format https://bugs.python.org/issue39240 closed by eric.smith #39242: Update news.gmane.org to news.gmane.io https://bugs.python.org/issue39242 closed by vstinner #39246: shutil.rmtree is inefficient because of using os.scandir inste https://bugs.python.org/issue39246 closed by Felipe A. Hernandez #39250: os.path.commonpath() not so common https://bugs.python.org/issue39250 closed by zach.ware #39251: outdated windows store links in WindowsApps folder https://bugs.python.org/issue39251 closed by steve.dower #39255: Windows and Unix run-time differences https://bugs.python.org/issue39255 closed by eryksun #39256: Exception handler set by set_exception_handler is called only https://bugs.python.org/issue39256 closed by asvetlov #39258: json serialiser errors with numpy int64 https://bugs.python.org/issue39258 closed by xtreak #39261: Dead assignment in pyinit_config https://bugs.python.org/issue39261 closed by benjamin.peterson #39262: Unused error message in _sharedexception_bind https://bugs.python.org/issue39262 closed by benjamin.peterson #39265: test_ssl failed on AMD64 RHEL8 Refleaks 2.7 https://bugs.python.org/issue39265 closed by vstinner #39269: Descriptor how-to guide wanting update for 3.6+ features https://bugs.python.org/issue39269 closed by rhettinger #39270: Dead assignment in config_init_module_search_paths https://bugs.python.org/issue39270 closed by vstinner #39271: Dead assignment in pattern_subx https://bugs.python.org/issue39271 closed by serhiy.storchaka #39272: Dead assignment in _ssl__SSLContext_load_verify_locations_impl https://bugs.python.org/issue39272 closed by vstinner #39284: Flexible indentation https://bugs.python.org/issue39284 closed by eric.smith

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Differences in what lint (e.g., mypy, flake8, etc) require from new code and what Cpython uses/returns - e.g., strings with single/double quotes.
by Michael 09 Jan '20

09 Jan '20

Hi all, Last year I was struggling to get some code to pass CI in pypa/packaging. There were other issues, but one that suprised me most was learning to ALWAYS use double quotes (") to get the code to pass the lint check (type checking). Anything using single quotes (') as string delimiters were not accepted as a STRING type. I am not questioning the demands of the lint checker - rather - I am offering my services (aka time) to work through core to make CPython pass it's own (I assume) PEP recommendations or guidelines. Again, this is not a bug-report - but an offer to assist with what I see as an inconsistency. If my assistance in this area is appreciated/desired I would appreciate one or more core developers to assist me with managing the PR process. Not for speed, but I would not want to burden just one core developer. My approach would entail opening a number of related 'issues' for different pieces: e.g., Lib, Modules, Python, Documentation where some Lib|Modules|Python pieces might need to be individual 'issues' due to size and/or complexity. I do not see this as happening 'overnight'. so-called simple things to fix: In Documentation: The return value is the result of the evaluated expression. Syntax errors are reported as exceptions. Example: x = 1 eval('x+1') 2 Change the text above to state eval("x+1") - assuming the lint process would no longer accept eval('x+1') as proper typed syntax. And, then, hoping this is still regarded as 'simple' make sure code such as ctypes.util.find_library() is consistent, returning strings terminated by double quotes rather than the single quotes as of now. >>> import ctypes.util >>> ctypes.util.find_library("c") >>> 'libc.a(shr.o)' >>> ctypes.util.find_library("ssl") >>> 'libssl.a(libssl.so)' Something more "complex" may be the list of names dir() returns: >>> >>> import sysconfig >>> dir(sysconfig)) ['_BASE_EXEC_PREFIX', '_BASE_PREFIX', '_CONFIG_VARS', '_EXEC_PREFIX', '_INSTALL_SCHEMES', '_PREFIX', '_PROJECT_BASE', '_PYTHON_BUILD', '_PY_VERSION', '_PY_VERSION_SHORT', '_PY_VERSION_SHORT_NO_DOT', '_SCHEME_KEYS', '_USER_BASE', '__all__', '__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__spec__', '_expand_vars', '_extend_dict', '_generate_posix_vars', '_get_default_scheme', '_get_sysconfigdata_name', '_getuserbase', '_init_non_posix', '_init_posix', '_is_python_source_dir', '_main', '_parse_makefile', '_print_dict', '_safe_realpath', '_subst_vars', '_sys_home', 'get_config_h_filename', 'get_config_var', 'get_config_vars', 'get_makefile_filename', 'get_path', 'get_path_names', 'get_paths', 'get_platform', 'get_python_version', 'get_scheme_names', 'is_python_build', 'os', 'pardir', 'parse_config_h', 'realpath', 'scheme', 'sys'] >>> Regards, Michael

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Dict __missing__ consistency issues.
by Bar Harel 08 Jan '20

08 Jan '20

Hey guys, I was just about to fix dict's get() to call __missing__ if a key doesn't exist (before returning the default value) but realized that although small, that patch can cause future issues. Right now there's an inconsistency: >>> from collections import UserDict >>> class A(dict): ... def __missing__(self, key): ... print(key) ... >>> class B(UserDict): ... def __missing__(self, key): ... print("UserDict", key) ... >>> a = A() >>> b = B() >>> a.get(123) >>> b.get(123) UserDict 123 >>> a.get(123, "abc") 'abc' >>> b.get(123, "abc") UserDict 123 The reason for this inconsistency is because the Mapping abc and dict behave differently. Dict's get doesn't call __getitem__ which causes the call not to route to __missing__. MutableMapping's get calls __getitem__, which UserDict implements as a check to __missing__ as well. According to the doc, the specification requires dict's __getitem__ to call __missing__. It doesn't say anything about get(). Should get() call __missing__? If it does, things like defaultdict.get() might break. It will however be more consistent with dict's specification. If it doesn't, we expect Mapping to not care about __missing__ as it's only a dict thing, which will require UserDict to override get(). Dict's get() will need to receive a doc update as well stating __missing__ is not called. Second question is: Is __missing__ only a dict thing, or is it part of the Mapping ABC? I would expect it to be a part of the Mapping ABC, with subclasses not having to implement it. Right now it's not. Looking forward for your inputs, Bar Harel

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Re: Dict __missing__ consistency issues.
by Bar Harel 08 Jan '20

08 Jan '20

> > [Bar Harel] > > As for get(). Current implementation of UserDict returns the default > value > > for get() if __missing__() raises KeyError. Which sounds reasonable to > me. > > After all, you would logically expect __missing__ to be called for get() > > as you tried to get a non-existing value. > > > [Ethan Furman] > I disagree. My understanding of the purpose behind get() is to get a value > or return the default specified in the get() call, not to create a new key > (which the default __missing__ does). > There is no default __missing__. That's what the __missing__ at defaultdict does. Like I said before: The fact __missing__ is not called for missing values is a bit funny in my opinion, but it doesn't actually matter cause we can't do anything about it without breaking lots of stuff (e.g. making defaultdict.get worthless).

1 0

Dict __missing__ consistency issues
by Bar Harel 08 Jan '20

08 Jan '20

Hey guys, I was just about to fix dict's get() to call __missing__ if a key doesn't exist (before returning the default value) but realized that although small, that patch can cause future issues. Right now there's an inconsistency: >>> from collections import UserDict >>> class A(dict): ... def __missing__(self, key): ... print(key) ... >>> class B(UserDict): ... def __missing__(self, key): ... print("UserDict", key) ... >>> a = A() >>> b = B() >>> a.get(123) >>> b.get(123) UserDict 123 >>> a.get(123, "abc") 'abc' >>> b.get(123, "abc") UserDict 123 The reason for this inconsistency is because the Mapping abc and dict behave differently. Dict's get doesn't call __getitem__ which causes the call not to route to __missing__. MutableMapping's get calls __getitem__, which UserDict implements as a check to __missing__ as well. According to the doc, the specification requires dict's __getitem__ to call __missing__. It doesn't say anything about get(). Should get() call __missing__? If it does, things like defaultdict.get() might break. It will however be more consistent with dict's specification. If it doesn't, we expect Mapping to not care about __missing__ as it's only a dict thing, which will require UserDict to override get(). Dict's get() will need to receive a doc update as well stating __missing__ is not called. Second question is: Is __missing__ only a dict thing, or is it part of the Mapping ABC? I would expect it to be a part of the Mapping ABC, with subclasses not having to implement it. Right now it's not. Looking forward for your inputs, Bar Harel

1 0

Should set objects maintain insertion order too?
by Larry Hastings 08 Jan '20

08 Jan '20

As of 3.7, dict objects are guaranteed to maintain insertion order. But set objects make no such guarantee, and AFAIK in practice they don't maintain insertion order either. Should they? I do have a use case for this. In one project I maintain a "ready" list of jobs; I need to iterate over it, but I also want fast lookup because I soemtimes remove jobs when they're subsequently marked "not ready". The existing set object would work fine here, except that it doesn't maintain insertion order. That means multiple runs of the program with the same inputs may result in running jobs in different orders, and this instability makes debugging more difficult. I've therefore switched from a set to a dict with all keys mapped to None, which provides all the set-like functionality I need. ISTM that all the reasons why dicts should maintain insertion order also apply to sets, and so I think we should probably do this. Your thoughts? //arry/ p.s. My dim recollection is that the original set object was a hacked-up copy of the dict object removing the ability to store values. So there's some precedent for dicts and sets behaving similarly. (Note: non-pejorative use of "hacked-up" here, that was a fine way to start.)

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Python Documentation and AIX specifics - how to proceed?
by Michael 07 Jan '20

07 Jan '20

First - best wishes all for a happy and healthy 2020! As my nickname implies - my primary means to contribute to Python is with regard to AIX. One of the things I recently came across is Misc/README.AIX which was last updated sometime between 2010 and 2014. I am thinking a facelift is in order. Assuming 2010-2011 as the original date - much has changed and many of the comments are no longer accurate. Before saying so, I would like to check here that - having all tests pass on the 3.8 bot implies that there are no outstanding issues. As to the historical issues in the current document - these could either be deleted, or a short text describing when they were resolved (e.g., Python 3.7, or just resolved, but noone knows exactly how or when - whether it was a Python change, or a platform (AIX) change. What I see as being more relevant is the description re: how to build Python for AIX - for the "do it youself"-ers. So, besides the direct question re: what to say about the old "known issues" and whether there are no known issues aka, no issues identified via the standard tests - I would appreciate feedback on what is considered appropriate - anno 2020 - for any Misc/README.platform text. Additionally, I am willing to work on other areas of the standard documentation where it is either needed or considered appropriate for platform specific details and/or examples. This is not something I would try to get done in a single PR, Instead I am thinking a single -longer term- issue - and multiple PR's to work through corrections and additions during 2020. Focus on Python 3.9 and beyond yet where appropriate backlevel to Python 3.8 or even 3.7. Sincerely, Michael

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Python-dev mailing lis archives earlier than late April 1999?
by Skip Montanaro 07 Jan '20

07 Jan '20

I could swear python-dev was older than late April 1999, yet that's as far back as the MM3 archives go. As evidence, here's an email from Jack Jansen on 28 April 1999 which was a reply to an earlier message not present in the current archive: https://mail.python.org/archives/list/python-dev@python.org/thread/EMH62JYF… Any pointers to older messages appreciated... Skip

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