memoryview & ctypes: incorrect itemsize for empty array #76963

eric-wieser · 2018-02-06T18:53:21Z

BPO	32782
Nosy	@terryjreedy, @amauryfa, @abalkin, @skrah, @meadori, @eric-wieser
PRs	bpo-32782: PEP3118 itemsize of an empty ctypes array should not be 0 #5576

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2018-02-06.18:53:21.025>
labels = ['interpreter-core', 'type-bug', '3.8', '3.9', '3.10', 'ctypes']
title = 'memoryview & ctypes: incorrect itemsize for empty array'
updated_at = <Date 2020-05-23.15:47:49.464>
user = 'https://github.com/eric-wieser'

bugs.python.org fields:

activity = <Date 2020-05-23.15:47:49.464>
actor = 'cheryl.sabella'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Interpreter Core', 'ctypes']
creation = <Date 2018-02-06.18:53:21.025>
creator = 'Eric.Wieser'
dependencies = []
files = []
hgrepos = []
issue_num = 32782
keywords = ['patch']
message_count = 9.0
messages = ['311740', '321290', '324705', '340230', '340231', '340232', '340235', '340236', '348004']
nosy_count = 8.0
nosy_names = ['terry.reedy', 'teoliphant', 'amaury.forgeotdarc', 'belopolsky', 'skrah', 'meador.inge', 'Eric.Wieser', 'Eric Wieser']
pr_nums = ['5576']
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue32782'
versions = ['Python 3.8', 'Python 3.9', 'Python 3.10']

Linked PRs

eric-wieser · 2018-02-06T18:53:21Z

Take the following simple structure:

    class Foo(ctypes.Structure):
        _fields_ = [('f', ctypes.uint32_t)]

And construct some arrays with it:

    def get_array_view(N):
        return memoryview((Foo * N)())

In most cases, this works as expected, returning the size of one item:

    >>> get_array_view(10).itemsize
    4
    >>> get_array_view(1).itemsize
    4

But when N=0, it returns the wrong result

    >>> get_array_view(0).itemsize
    0

Which contradicts its .format, which still describes a 4-byte struct

    >>> get_array_view(0).format
    'T{>I:one:}'

This causes a downstream problem in numpy:

    >>> np.array(get_array_view(0))
    RuntimeWarning: Item size computed from the PEP 3118 buffer format string does not match the actual item size.

eric-wieser · 2018-07-08T21:48:59Z

Pinging, as recommended by https://devguide.python.org/pullrequest/#reviewing. Ideally this and https://bugs.python.org/issue32780 would make the same patch release.

eric-wieser · 2018-09-06T17:03:02Z

Pinging again, for lack of a clearer path forward

terryjreedy · 2019-04-14T20:04:27Z

This issue is about the itemsize attribute of instances of the built-in memoryview class. Ctypes in only involved in providing format information. Hence the nosy additions.

On Win10 with 3.8, ctypes has no uint attributes. Using 'c_int32' instead, I see the same behavior (itemsize 0 for empty structure).

About itemsize, https://www.python.org/dev/peps/pep-3118/ says

"This is a storage for the itemsize (in bytes) of each element of the shared memory. It is technically un-necessary as it can be obtained using PyBuffer_SizeFromFormat, however an exporter may know this information without parsing the format string and it is necessary to know the itemsize for proper interpretation of striding. Therefore, storing it is more convenient and faster."

The first line could be seen as implying that itemsize is undefined if there are no items (and as justifying numbytes/numitems otherwise). The 0 return could be seen as equivalent to a None return from a python-coded function. If so, it is not a bug, and there might be code that would break if it is changed.

On the other hand, the next lines imply that itemsize is *usually*, though not necessarily, a cache for PyBuffer_SizeFromFormat. This could be seen as implying that in the absence of other information, the itemsize should be calculated from the format, making 0 a bug.

terryjreedy · 2019-04-14T20:14:42Z

This is actually about memoryview.itemsize within ctypes.

terryjreedy · 2019-04-14T20:25:24Z

https://docs.python.org/3/library/stdtypes.html#typememoryview
says "itemsize The size in bytes of each element of the memoryview"
Revising the code example to use an empty array:
>>> import array, struct
>>> m = memoryview(array.array('H', [0])
>>> m.itemsize
2
I agree that itemsize should also be non-zero for ctype formats.

skrah · 2019-04-14T21:12:57Z

I agree that it is a ctypes issue, itemsize should be equal to struct.calcsize(fmt), which is never 0 for normal PEP-3118 types like the one in the example.

[Pedantically, I think that the grammar would allow for an empty record "T{}" that would have itemsize 0 but is of little use inside numpy.]

EricWieser · 2019-04-14T21:29:15Z

Revising the code example to use an empty array

I think you mean

>>> import array
>>> memoryview(array.array('H', [])).itemsize
2

Your example is an array containing 0, not an empty array - but the conclusion is the same.

It is technically un-necessary as it can be obtained using PyBuffer_SizeFromFormat

This obviously predicates on PyBuffer_SizeFromFormat being implemented, which according to the docs it is not.

I think that the grammar would allow for an empty record "T{}" that would have itemsize 0 but is of little use inside numpy.

It also allows for records of empty arrays, "T{(0)d:data:}". While these are of little use, they _are_ supported by both ctypes and numpy, so we should support them in the PEP-3118 interface used between them.

EricWieser · 2019-07-16T05:53:15Z

Pinging again, now that the patch has undergone a revision with some cleanup thanks to @skrah

…H-5576) The itemsize returned in a memoryview of a ctypes array is now computed from the item type, instead of dividing the total size by the length and assuming that the length is not zero.

…be 0 (pythonGH-5576) The itemsize returned in a memoryview of a ctypes array is now computed from the item type, instead of dividing the total size by the length and assuming that the length is not zero. (cherry picked from commit 84bc6a4) Co-authored-by: Eric Wieser <wieser.eric@gmail.com>

… be 0 (GH-5576) (#100451) gh-76963: PEP3118 itemsize of an empty ctypes array should not be 0 (GH-5576) The itemsize returned in a memoryview of a ctypes array is now computed from the item type, instead of dividing the total size by the length and assuming that the length is not zero. (cherry picked from commit 84bc6a4) Co-authored-by: Eric Wieser <wieser.eric@gmail.com>

… be 0 (GH-5576) (GH-100452) gh-76963: PEP3118 itemsize of an empty ctypes array should not be 0 (GH-5576) The itemsize returned in a memoryview of a ctypes array is now computed from the item type, instead of dividing the total size by the length and assuming that the length is not zero. (cherry picked from commit 84bc6a4) Co-authored-by: Eric Wieser <wieser.eric@gmail.com>

mattip · 2022-12-23T11:02:09Z

Thanks for the fix that closed this. @eric-wieser do you remember where this impacted NumPy? I don't see the relevant issue or PR.

eric-wieser · 2022-12-23T11:35:01Z

I think the workaround in numpy needs to stay till after #5561

eric-wieser · 2022-12-23T11:39:44Z

The reference in numpy is here:

https://github.com/numpy/numpy/blob/85b26f4afc6e98694eab7a6d6abefbd3fed31fde/numpy/core/_dtype_ctypes.py#L21

* Correct CVE-2020-10735 documentation (python#100306) * pythongh-94912: Added marker for non-standard coroutine function detection (python#99247) This introduces a new decorator `@inspect.markcoroutinefunction`, which, applied to a sync function, makes it appear async to `inspect.iscoroutinefunction()`. * Docs: Don't upload CI artifacts (python#100330) * pythongh-89727: Fix os.walk RecursionError on deep trees (python#99803) Use a stack to implement os.walk iteratively instead of recursively to avoid hitting recursion limits on deeply nested trees. * pythongh-69929: re docs: Add more specific definition of \w (python#92015) Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com> * pythongh-89051: Add ssl.OP_LEGACY_SERVER_CONNECT (python#93927) Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com> Co-authored-by: Christian Heimes <christian@python.org> Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com> Fixes python#89051 * pythongh-88211: Change lower-case and upper-case to match recommendations in imaplib docs (python#99625) * pythongh-100348: Fix ref cycle in `asyncio._SelectorSocketTransport` with `_read_ready_cb` (python#100349) * pythongh-99925: Fix inconsistency in `json.dumps()` error messages (pythonGH-99926) * Clarify that every thread has its own default context in contextvars (python#99246) * pythongh-99576: Fix cookiejar file that was not truncated for some classes (pythonGH-99616) Co-authored-by: Łukasz Langa <lukasz@langa.pl> * pythongh-100188: Reduce misses in BINARY_SUBSCR_(LIST/TUPLE)_INT (python#100189) Don't specialize if the index is negative. * pythongh-99991: improve docs on str.encode and bytes.decode (python#100198) Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM> * pythongh-91081: Add note on WeakKeyDictionary behavior when deleting a replaced entry (python#91499) Co-authored-by: Pieter Eendebak <P.T.eendebak@tudelft.nl> Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com> * pythongh-85267: Improvements to inspect.signature __text_signature__ handling (python#98796) This makes a couple related changes to inspect.signature's behaviour when parsing a signature from `__text_signature__`. First, `inspect.signature` is documented as only raising ValueError or TypeError. However, in some cases, we could raise RuntimeError. This PR changes that, thereby fixing python#83685. (Note that the new ValueErrors in RewriteSymbolics are caught and then reraised with a message) Second, `inspect.signature` could randomly drop parameters that it didn't understand (corresponding to `return None` in the `p` function). This is the core issue in python#85267. I think this is very surprising behaviour and it seems better to fail outright. Third, adding this new failure broke a couple tests. To fix them (and to e.g. allow `inspect.signature(select.epoll.register)` as in python#85267), I add constant folding of a couple binary operations to RewriteSymbolics. (There's some discussion of making signature expression evaluation arbitrary powerful in python#68155. I think that's out of scope. The additional constant folding here is pretty straightforward, useful, and not much of a slippery slope) Fourth, while python#85267 is incorrect about the cause of the issue, it turns out if you had consecutive newlines in __text_signature__, you'd get `tokenize.TokenError`. Finally, the `if name is invalid:` code path was dead, since `parse_name` never returned `invalid`. * pythonGH-100363: Speed up `asyncio.get_running_loop` (python#100364) * pythonGH-100133: fix `asyncio` subprocess losing `stderr` and `stdout` output (python#100154) * pythongh-100374: Fixed a bug in socket.getfqdn() (pythongh-100375) * pythongh-100129: Add tests for pickling all builtin types and functions (pythonGH-100142) * Remove unused variable from `dis._find_imports` (python#100396) * pythongh-78878: Fix crash when creating an instance of `_ctypes.CField` (python#14837) * pythonGH-69564: Clarify use of octal format of mode argument in help(os.chmod) (python#20621) Co-authored-by: Kumar Aditya <59607654+kumaraditya303@users.noreply.github.com> * pythonGH-99554: Pack location tables more effectively (pythonGH-99556) * Correct typo in typing.py (python#100423) In the docstring of `ParamSpec`, the name of `P = ParamSpec('P')` was mistakenly written as `'T'`. * pythongh-99761: Add `_PyLong_IsPositiveSingleDigit` function to check for single digit integers (python#100064) * pythonGH-99770: Make the correct call specialization fail kind show up in the stats (pythonGH-99771) * pythongh-78997: fix bad rebase of moved test file (python#100424) * pythongh-100344: Add C implementation for `asyncio.current_task` (python#100345) Co-authored-by: pranavtbhat * pythonGH-99554: Trim trailing whitespace (pythonGH-100435) Automerge-Triggered-By: GH:brandtbucher * pythongh-85432: Harmonise parameter names between C and pure-Python implementations of `datetime.time.strftime`, `datetime.datetime.fromtimestamp` (python#99993) * pythongh-57762: fix misleading tkinter.Tk docstring (python#98837) Mentioned as a desired change by terryjreedy on the corresponding issue, since Tk is not a subclass of Toplevel. * pythongh-48496: Added example and link to faq for UnboundLocalError in reference (python#93068) * Fix typo in 3.12 What's New (python#100449) * pythongh-76963: PEP3118 itemsize of an empty ctypes array should not be 0 (pythonGH-5576) The itemsize returned in a memoryview of a ctypes array is now computed from the item type, instead of dividing the total size by the length and assuming that the length is not zero. * pythonGH-100459: fix copy-paste errors in specialization stats (pythonGH-100460) * pythongh-99110: Initialize `frame->previous` in init_frame to fix segmentation fault when accessing `frame.f_back` (python#100182) * pythongh-98712: Clarify "readonly bytes-like object" semantics in C arg-parsing docs (python#98710) * pythongh-92216: improve performance of `hasattr` for type objects (pythonGH-99979) * pythongh-100288: Specialise LOAD_ATTR_METHOD for managed dictionaries (pythonGH-100289) * Revert "pythongh-100288: Specialise LOAD_ATTR_METHOD for managed dictionaries (pythonGH-100289)" (python#100468) This reverts commit c3c7848. * pythongh-94155: Reduce hash collisions for code objects (python#100183) * Uses a better hashing algorithm to get better dispersion and remove commutativity. * Incorporates `co_firstlineno`, `Py_SIZE(co)`, and bytecode instructions. * This is now the entire set of criteria used in `code_richcompare`, except for `_PyCode_ConstantKey` (which would incorporate the types of `co_consts` rather than just their values). * pythongh-83076: 3.8x speed improvement in (Async)Mock instantiation (python#100252) * pythongh-99482: remove `jython` compatibility parts from stdlib and tests (python#99484) * bpo-40447: accept all path-like objects in compileall.compile_file (python#19883) Signed-off-by: Filipe Laíns <lains@archlinux.org> Signed-off-by: Filipe Laíns <lains@riseup.net> Co-authored-by: Irit Katriel <1055913+iritkatriel@users.noreply.github.com> Co-authored-by: Shantanu <12621235+hauntsaninja@users.noreply.github.com> * pythonGH-100425: Improve accuracy of builtin sum() for float inputs (pythonGH-100426) * pythongh-68320, pythongh-88302 - Allow for private `pathlib.Path` subclassing (pythonGH-31691) Users may wish to define subclasses of `pathlib.Path` to add or modify existing methods. Before this change, attempting to instantiate a subclass raised an exception like: AttributeError: type object 'PPath' has no attribute '_flavour' Previously the `_flavour` attribute was assigned as follows: PurePath._flavour = xxx not set!! xxx PurePosixPath._flavour = _PosixFlavour() PureWindowsPath._flavour = _WindowsFlavour() This change replaces it with a `_pathmod` attribute, set as follows: PurePath._pathmod = os.path PurePosixPath._pathmod = posixpath PureWindowsPath._pathmod = ntpath Functionality from `_PosixFlavour` and `_WindowsFlavour` is moved into `PurePath` as underscored-prefixed classmethods. Flavours are removed. Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com> Co-authored-by: Brett Cannon <brett@python.org> Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com> Co-authored-by: Eryk Sun <eryksun@gmail.com> * pythongh-99947: Ensure unreported errors are chained for SystemError during import (pythonGH-99946) * Add "strict" to dotproduct(). Add docstring. Factor-out common code. (pythonGH-100480) * pythongh-94808: improve test coverage of number formatting (python#99472) * pythongh-100454: Start running SSL tests with OpenSSL 3.1.0-beta1 (python#100456) * pythongh-100268: Add is_integer method to int (python#100439) This improves the lives of type annotation users of `float` - which type checkers implicitly treat as `int|float` because that is what most code actually wants. Before this change a `.is_integer()` method could not be assumed to exist on things annotated as `: float` due to the method not existing on both types. * pythongh-77771: Add enterabs example in sched (python#92716) Co-authored-by: Shantanu <12621235+hauntsaninja@users.noreply.github.com> * pythonGH-91166: Implement zero copy writes for `SelectorSocketTransport` in asyncio (python#31871) Co-authored-by: Guido van Rossum <gvanrossum@gmail.com> * pythonGH-91166: Implement zero copy writes for `SelectorSocketTransport` in asyncio (python#31871) Co-authored-by: Guido van Rossum <gvanrossum@gmail.com> * Misc Itertools recipe tweaks (pythonGH-100493) * pythongh-100357: Convert several functions in `bltinsmodule` to AC (python#100358) * Remove wrong comment about `repr` in `test_unicode` (python#100495) * pythongh-99908: Tutorial: Modernize the 'data-record class' example (python#100499) Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com> * pythongh-100474: Fix handling of dirs named index.html in http.server (pythonGH-100475) If you had a directory called index.html or index.htm within a directory, it would cause http.server to return a 404 Not Found error instead of the directory listing. This came about due to not checking that the index was a regular file. I have also added a test case for this situation. Automerge-Triggered-By: GH:merwok * pythongh-100287: Fix unittest.mock.seal with AsyncMock (python#100496) * pythongh-99535: Add test for inheritance of annotations and update documentation (python#99990) * pythongh-100428: Make float documentation more accurate (python#100437) Previously, the grammar did not accept `float("10")`. Also implement mdickinson's suggestion of removing the indirection. * [Minor PR] Quotes in documentation changed into code blocks (python#99536) Minor formatting fix in documentation Co-authored-by: Shantanu <12621235+hauntsaninja@users.noreply.github.com> * pythongh-100472: Fix docs claim that compileall parameters could be bytes (python#100473) * pythongh-100519: simplification to `eff_request_host` in cookiejar.py (python#99588) `IPV4_RE` includes a `.`, and the `.find(".") == -1` included here is already testing to make sure there's no dot, so this part of the expression is tautological. Instead use more modern `in` syntax to make it clear what the check is doing here. The simplified implementation more clearly matches the wording in RFC 2965. Co-authored-by: hauntsaninja <hauntsaninja@gmail.com> * pythongh-99308: Clarify re docs for byte pattern group names (python#99311) * pythongh-92446: Improve argparse choices docs; revert bad change to lzma docs (python#94627) Based on the definition of the collections.abc classes, it is more accurate to use "sequence" instead of "container" when describing argparse choices. A previous attempt at fixing this in python#92450 was mistaken; this PR reverts that change. Co-authored-by: Shantanu <12621235+hauntsaninja@users.noreply.github.com> * Fix name of removed `inspect.Signature.from_builtin` method in 3.11.0a2 changelog (python#100525) * pythongh-100520: Fix `rst` markup in `configparser` docstrings (python#100524) * pythongh-99509: Add `__class_getitem__` to `multiprocessing.queues.Queue` (python#99511) * pythongh-94603: micro optimize list.pop (pythongh-94604) * Remove `NoneType` redefinition from `clinic.py` (python#100551) * pythongh-100553: Improve accuracy of sqlite3.Row iter test (python#100555) * pythonGH-98831: Modernize a ton of simpler instructions (python#100545) * load_const and load_fast aren't families for now * Don't decref unmoved names * Modernize GET_ANEXT * Modernize GET_AWAITABLE * Modernize ASYNC_GEN_WRAP * Modernize YIELD_VALUE * Modernize POP_EXCEPT (in more than one way) * Modernize PREP_RERAISE_STAR * Modernize LOAD_ASSERTION_ERROR * Modernize LOAD_BUILD_CLASS * Modernize STORE_NAME * Modernize LOAD_NAME * Modernize LOAD_CLASSDEREF * Modernize LOAD_DEREF * Modernize STORE_DEREF * Modernize COPY_FREE_VARS (mark it as done) * Modernize LIST_TO_TUPLE * Modernize LIST_EXTEND * Modernize SET_UPDATE * Modernize SETUP_ANNOTATIONS * Modernize DICT_UPDATE * Modernize DICT_MERGE * Modernize MAP_ADD * Modernize IS_OP * Modernize CONTAINS_OP * Modernize CHECK_EXC_MATCH * Modernize IMPORT_NAME * Modernize IMPORT_STAR * Modernize IMPORT_FROM * Modernize JUMP_FORWARD (mark it as done) * Modernize JUMP_BACKWARD (mark it as done) Signed-off-by: Filipe Laíns <lains@archlinux.org> Signed-off-by: Filipe Laíns <lains@riseup.net> Co-authored-by: Jeremy Paige <ucodery@gmail.com> Co-authored-by: Carlton Gibson <carlton@noumenal.es> Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com> Co-authored-by: Jon Burdo <jon@jonburdo.com> Co-authored-by: Stanley <46876382+slateny@users.noreply.github.com> Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com> Co-authored-by: Thomas Grainger <tagrain@gmail.com> Co-authored-by: Brad Wolfe <brad.wolfe@gmail.com> Co-authored-by: Richard Kojedzinszky <rkojedzinszky@users.noreply.github.com> Co-authored-by: František Nesveda <fnesveda@users.noreply.github.com> Co-authored-by: Pablo Galindo Salgado <Pablogsal@gmail.com> Co-authored-by: Nikita Sobolev <mail@sobolevn.me> Co-authored-by: Łukasz Langa <lukasz@langa.pl> Co-authored-by: Dennis Sweeney <36520290+sweeneyde@users.noreply.github.com> Co-authored-by: Bisola Olasehinde <horlasehinde@gmail.com> Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM> Co-authored-by: Pieter Eendebak <P.T.eendebak@tudelft.nl> Co-authored-by: Shantanu <12621235+hauntsaninja@users.noreply.github.com> Co-authored-by: Kumar Aditya <59607654+kumaraditya303@users.noreply.github.com> Co-authored-by: Dominic Socular <BBH@awsl.rip> Co-authored-by: Serhiy Storchaka <storchaka@gmail.com> Co-authored-by: Hai Shi <shihai1992@gmail.com> Co-authored-by: amaajemyfren <32741226+amaajemyfren@users.noreply.github.com> Co-authored-by: Brandt Bucher <brandtbucher@microsoft.com> Co-authored-by: david-why <david_why@outlook.com> Co-authored-by: Pieter Eendebak <pieter.eendebak@gmail.com> Co-authored-by: penguin_wwy <940375606@qq.com> Co-authored-by: Eli Schwartz <eschwartz93@gmail.com> Co-authored-by: Itamar Ostricher <itamarost@gmail.com> Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com> Co-authored-by: Eric Wieser <wieser.eric@gmail.com> Co-authored-by: Irit Katriel <1055913+iritkatriel@users.noreply.github.com> Co-authored-by: Bill Fisher <william.w.fisher@gmail.com> Co-authored-by: Petr Viktorin <encukou@gmail.com> Co-authored-by: Ken Jin <kenjin@python.org> Co-authored-by: Carl Meyer <carl@oddbird.net> Co-authored-by: Filipe Laíns <lains@riseup.net> Co-authored-by: Raymond Hettinger <rhettinger@users.noreply.github.com> Co-authored-by: Barney Gale <barney.gale@gmail.com> Co-authored-by: Brett Cannon <brett@python.org> Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com> Co-authored-by: Eryk Sun <eryksun@gmail.com> Co-authored-by: Sebastian Berg <sebastianb@nvidia.com> Co-authored-by: Illia Volochii <illia.volochii@gmail.com> Co-authored-by: JosephSBoyle <48555120+JosephSBoyle@users.noreply.github.com> Co-authored-by: James Frost <git@frost.cx> Co-authored-by: MonadChains <monadchains@gmail.com> Co-authored-by: Bart Broere <mail@bartbroere.eu> Co-authored-by: Glyph <code@glyph.im> Co-authored-by: hauntsaninja <hauntsaninja@gmail.com> Co-authored-by: Ilya Kulakov <kulakov.ilya@gmail.com> Co-authored-by: Guy Yagev <yourlefthandman8@gmail.com> Co-authored-by: Jakub Kuczys <me@jacken.men>

eric-wieser mannequin added topic-ctypes type-bug An unexpected behavior, bug, or error labels Feb 6, 2018

terryjreedy added interpreter-core (Objects, Python, Grammar, and Parser dirs) 3.8 only security fixes and removed topic-ctypes labels Apr 14, 2019

terryjreedy changed the title ~~ctypes: memoryview gives incorrect PEP3118 itemsize for array of length zero~~ memoryview gives incorrect PEP3118 itemsize for empty array Apr 14, 2019

terryjreedy added the topic-ctypes label Apr 14, 2019

terryjreedy changed the title ~~memoryview gives incorrect PEP3118 itemsize for empty array~~ memoryview & ctypes: incorrect PEP3118 itemsize for empty array Apr 14, 2019

terryjreedy changed the title ~~memoryview & ctypes: incorrect PEP3118 itemsize for empty array~~ memoryview & ctypes: incorrect itemsize for empty array Apr 14, 2019

csabella added 3.9 only security fixes 3.10 only security fixes labels May 23, 2020

ezio-melotti transferred this issue from another repository Apr 10, 2022

eric-wieser mentioned this issue Apr 11, 2022

bpo-32782: PEP3118 itemsize of an empty ctypes array should not be 0 #5576

Merged

mdickinson closed this as completed in #5576 Dec 23, 2022

bedevere-bot mentioned this issue Dec 23, 2022

[3.10] gh-76963: PEP3118 itemsize of an empty ctypes array should not be 0 (GH-5576) #100451

Merged

bedevere-bot mentioned this issue Dec 23, 2022

[3.11] gh-76963: PEP3118 itemsize of an empty ctypes array should not be 0 (GH-5576) #100452

Merged

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

memoryview & ctypes: incorrect itemsize for empty array #76963

memoryview & ctypes: incorrect itemsize for empty array #76963

eric-wieser mannequin commented Feb 6, 2018 •

edited by bedevere-bot

eric-wieser mannequin commented Feb 6, 2018

eric-wieser mannequin commented Jul 8, 2018

eric-wieser mannequin commented Sep 6, 2018

terryjreedy commented Apr 14, 2019

terryjreedy commented Apr 14, 2019

terryjreedy commented Apr 14, 2019

skrah mannequin commented Apr 14, 2019

EricWieser mannequin commented Apr 14, 2019

EricWieser mannequin commented Jul 16, 2019

mattip commented Dec 23, 2022

eric-wieser commented Dec 23, 2022

eric-wieser commented Dec 23, 2022

memoryview & ctypes: incorrect itemsize for empty array #76963

memoryview & ctypes: incorrect itemsize for empty array #76963

Comments

eric-wieser mannequin commented Feb 6, 2018 • edited by bedevere-bot

Linked PRs

eric-wieser mannequin commented Feb 6, 2018

eric-wieser mannequin commented Jul 8, 2018

eric-wieser mannequin commented Sep 6, 2018

terryjreedy commented Apr 14, 2019

terryjreedy commented Apr 14, 2019

terryjreedy commented Apr 14, 2019

skrah mannequin commented Apr 14, 2019

EricWieser mannequin commented Apr 14, 2019

EricWieser mannequin commented Jul 16, 2019

mattip commented Dec 23, 2022

eric-wieser commented Dec 23, 2022

eric-wieser commented Dec 23, 2022

eric-wieser mannequin commented Feb 6, 2018 •

edited by bedevere-bot