On 18 Jun 2017, at 19:21, Barry Scott
wrote: On 14 Jun 2017, at 07:33, Nick Coghlan
mailto:ncoghlan@gmail.com> wrote: On 14 June 2017 at 13:02, Mahmoud Hashemi
mailto:mahmoud@hatnote.com> wrote: That would be amazing! If there's anything I can do to help make that happen, please let me know. It'll almost certainly save that much time for me alone down the line, anyway :)
The `IMPORT_FROM` opcode's error handling would probably be the best place to start poking around: https://github.com/python/cpython/blob/master/Python/ceval.c#L5055 https://github.com/python/cpython/blob/master/Python/ceval.c#L5055
If you can prove the concept there, that would:
1. Directly handle the "from x import y" and "import x.y as name" cases 2. Provide a starting point for factoring out a "report missing module attribute" helper that could be shared with ModuleType
As an example of querying _frozen_importlib state from C code, I'd point to https://github.com/python/cpython/blob/master/Python/import.c#L478 https://github.com/python/cpython/blob/master/Python/import.c#L478
I had thought that the solution would be in the .py implementation of the import machinery not in the core C code.
I was going to simply keep track of the names of the modules that are being imported and raise an exception if an import attempted to import a module that had not completed being imported. It seems from a quick loom at the code that this would be practical.
Are you saying that there is a subtle point about import and detection of cycles that means the work must be done in C?
It seemed that PyImport_ImportModuleLevelObject() always calls out the interp->importlib. For example: value = _PyObject_CallMethodIdObjArgs(interp->importlib, &PyId__lock_unlock_module, abs_name, NULL); Where interp->importlib is the frozen importlib.py code I thought. I'd assumed that I would need to change the importlib.py code and build that as the frozen version to implement this. Barry
Barry
Cheers, Nick.
P.S. I also double checked that ImportError & AttributeError have compatible binary layouts, so dual inheritance from them works :)
-- Nick Coghlan | ncoghlan@gmail.com mailto:ncoghlan@gmail.com | Brisbane, Australia _______________________________________________ Python-ideas mailing list Python-ideas@python.org mailto:Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
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