[issue32780] ctypes: memoryview gives incorrect PEP3118 format strings for both packed and unpacked structs

Change by Ned Deily : -- nosy: +vinay.sajip ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe:

[issue32780] ctypes: memoryview gives incorrect PEP3118 format strings for both packed and unpacked structs

mattip added the comment: Is there a ctypes or PEP-3118 core-dev who could review the issue and the PR solution? -- nosy: +mattip ___ Python tracker ___

[issue32780] ctypes: memoryview gives incorrect PEP3118 format strings for both packed and unpacked structs

Stefan Krah added the comment: Since Terry added me: Yes, this is clearly a bug, but it is a ctypes issue and not a memoryview issue. ctypes issues unfortunately tend to take some time until someone reviews. -- ___ Python tracker

[issue32780] ctypes: memoryview gives incorrect PEP3118 format strings for both packed and unpacked structs

Terry J. Reedy added the comment: Fixing one case is better than fixing no cases. -- nosy: +skrah, terry.reedy ___ Python tracker ___

[issue32780] ctypes: memoryview gives incorrect PEP3118 format strings for both packed and unpacked structs

Change by Terry J. Reedy : -- versions: -Python 3.6 ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe:

[issue32780] ctypes: memoryview gives incorrect PEP3118 format strings for both packed and unpacked structs

Eric Wieser added the comment: > It should be fairly simple to modify the code to use a format of "B" > for unions, so that it at least matches the itemsize Seems reasonable, although: * I think it should be "B" or "()B" * I'd rather leave that for a later patch. While it would be correct,

[issue32780] ctypes: memoryview gives incorrect PEP3118 format strings for both packed and unpacked structs

Carl Banks added the comment: I guess I'll weigh in since I was pinged. I agree with the approach in the patch. All the memoryview does is to use the format field verbatim from the underlying buffer, so if the format field is inaccurate then the only thing to do is to fix the object

[issue32780] ctypes: memoryview gives incorrect PEP3118 format strings for both packed and unpacked structs

Change by Alexander Belopolsky : -- assignee: -> belopolsky ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe:

[issue32780] ctypes: memoryview gives incorrect PEP3118 format strings for both packed and unpacked structs

Alexander Belopolsky added the comment: Unfortunately, the PEP authors did very little in terms of implementing the PEP and neither CPython nor numpy has a fully compliant implementation. -- nosy: +aerojockey, teoliphant ___ Python tracker

[issue32780] ctypes: memoryview gives incorrect PEP3118 format strings for both packed and unpacked structs

Eric Wieser added the comment: Pinging, as recommended by https://devguide.python.org/pullrequest/#reviewing. PEP3118 as a protocol is far less useful if the canonical implementation is non-compliant. -- ___ Python tracker

[issue32780] ctypes: memoryview gives incorrect PEP3118 format strings for both packed and unpacked structs

Change by Terry J. Reedy : -- nosy: +amaury.forgeotdarc, belopolsky, meador.inge versions: -Python 3.4, Python 3.5 ___ Python tracker

[issue32780] ctypes: memoryview gives incorrect PEP3118 format strings for both packed and unpacked structs

Change by Eric Wieser : -- type: -> behavior ___ Python tracker ___ ___

[issue32780] ctypes: memoryview gives incorrect PEP3118 format strings for both packed and unpacked structs

Change by Eric Wieser : -- keywords: +patch pull_requests: +5383 stage: -> patch review ___ Python tracker ___

[issue32780] ctypes: memoryview gives incorrect PEP3118 format strings for both packed and unpacked structs

New submission from Eric Wieser : Discovered [here](https://github.com/numpy/numpy/issues/10528) Consider the following structure, and a memoryview created from it: class foo(ctypes.Structure): _fields_ = [('one', ctypes.c_uint8),