[issue18181] super vs. someclass.__getattribute__
Ronald Oussoren added the comment: There now is a PEP for this issue: http://www.python.org/dev/peps/pep-0447/. The current version of the PEP describes a different API than documented by the attached proposal and the prove of concept code. I'm working on an updated implementation. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue18181] super vs. someclass.__getattribute__
Ronald Oussoren added the comment: issue18181-locallookup-only-super.txt implements the current version of PEP 447, but only for the super object. In this version of the patch normal attribute lookup (object.__getattribute__ and PyObject_GenericGetAttr) are not yet affected. Another open issue: the documentation for the super object itself does not yet mention __locallookup__; it probably should but I don't know yet how to cleanly add it there. -- Added file: http://bugs.python.org/file30928/issue18181-locallookup-only-super.txt ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue18181] super vs. someclass.__getattribute__
Ronald Oussoren added the comment: Updated version of the patch, with some semantic changes and tests for the Python level API. Known issues: * Patches uses tabs for indentation * No tests for the C level API * I don't like implementation of slot_tp_getattro_super -- Added file: http://bugs.python.org/file30766/issue-18181-poc-v4.txt ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue18181] super vs. someclass.__getattribute__
Changes by Ronald Oussoren ronaldousso...@mac.com: Removed file: http://bugs.python.org/file30546/issue-18181-poc.txt ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue18181] super vs. someclass.__getattribute__
Changes by Ronald Oussoren ronaldousso...@mac.com: Removed file: http://bugs.python.org/file30555/issue-18181-poc-v3.txt ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue18181] super vs. someclass.__getattribute__
Changes by Ronald Oussoren ronaldousso...@mac.com: Removed file: http://bugs.python.org/file30528/supers.py ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue18181] super vs. someclass.__getattribute__
Changes by Ronald Oussoren ronaldousso...@mac.com: Removed file: http://bugs.python.org/file30556/super-hook-proposal.rst ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue18181] super vs. someclass.__getattribute__
Ronald Oussoren added the comment: Also updated the draft PEP text -- Added file: http://bugs.python.org/file30767/super-hook-proposal.rst ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue18181] super vs. someclass.__getattribute__
Ronald Oussoren added the comment: added draft of a pep-style proposal -- Added file: http://bugs.python.org/file30556/super-hook-proposal.rst ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue18181] super vs. someclass.__getattribute__
Ronald Oussoren added the comment: Slightly updated patch (different names, added some documentation) -- Added file: http://bugs.python.org/file30555/issue-18181-poc-v3.txt ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue18181] super vs. someclass.__getattribute__
Ronald Oussoren added the comment: I've attached a first very rough patch to demonstrate what I was rambling about. With this patch and a patched version of PyObjC I can use the builtin super class with the proxy classes for Objective-C classes. Open issues: * Does this need a pep? * The name of the new slot sucks, need to find a better one * Should it be possible to define the slot in Python code? Probably, the 'super.py' file is a crude hack but I can imagine more realistic scenarios where implementing the slot in Python would be useful. * There are no tests, and no documentation updates -- keywords: +patch Added file: http://bugs.python.org/file30546/issue-18181-poc.txt ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue18181] super vs. someclass.__getattribute__
Ronald Oussoren added the comment: Second version of the poc adds a way to implement the hook in Python code, and supers_updated.py uses that hook. Still no tests, no documentation and with awfull naming :-) -- Added file: http://bugs.python.org/file30547/supers_updated.py ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue18181] super vs. someclass.__getattribute__
Ronald Oussoren added the comment: . -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue18181] super vs. someclass.__getattribute__
Amaury Forgeot d'Arc added the comment: Is it possible to avoid a new slot? for example, super() could walk the tp_base- chain and call tp_getattro each time the value changes. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue18181] super vs. someclass.__getattribute__
Ronald Oussoren added the comment: I don't think it is possible to avoid adding a new slot. The default implementation of tp_getattro (PyObject_GenericGetAttr) looks in the instance dict, while super does not (because it wants a less specific implementation). PyObject_GenericGetAttr will also walk the entire MRO, while super.__getattribute__ does not start search at the first entry in the MRO. Although I'd love to be proven wrong ;-) -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue18181] super vs. someclass.__getattribute__
New submission from Ronald Oussoren: Super() walks the MRO and looks for the looked-up attribute in the __dict__ of types on the MRO. This can cause problems when classes implement __getattribute__: a class on the MRO can implement a method that super() won't find because it isn't in the class __dict__ (yet). I'm running into this with PyObjC: the __dict__ for the Python proxies for Objective-C classes are filled lazily (*) by tp_getattro (__getattribute__ in Python) to speed up the bridge and because ObjC is almost as dynamic as Python and methods might appear during runtime (without there being a hook for detecting such changes). A possible solution to this: * Add a tp_getattro_super (**) slot to PyTypeObject, with the same signature as tp_getattro, but that only looks at this particular class (as opposed to tp_getattro that walks the entire MRO and looks in the object's __dict__) (***) * The tp_gettro of super calls tp_getattro_super of types of along the MRO when that slot is not NULL, and uses the current implementation (look in tp_dict) when the slot is NULL. Would such a change be acceptable? Open issues: * Does the new slot get exposed to Python code (and if so, under which name)? * Should PyObject_GenericGetAttr use the new slot as well? Footnotes: (*) The current release of PyObjC (2.5) eagerly tries to keep the proxy class __dict__ up to date, an upcoming major release will be as lazy as possible to speed up the bridge. The problem can with some effert be triggered with PyObjC 2.5, and triggering it is easy in the upcoming major release (**) Or some better name (***) I'm being very sloppy in my use of terminology here, hopefully my proposal is clear enough anyway. -- components: Interpreter Core messages: 190905 nosy: ronaldoussoren priority: normal severity: normal stage: needs patch status: open title: super vs. someclass.__getattribute__ type: behavior versions: Python 3.4 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue18181] super vs. someclass.__getattribute__
Amaury Forgeot d'Arc added the comment: Do you have an example in pure Python code? -- nosy: +amaury.forgeotdarc ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue18181] super vs. someclass.__getattribute__
Ronald Oussoren added the comment: I didn't, but the attached script should do the trick. The code suffers badly from copypaste editing, but more or less has the same behavior as PyObjC. It defines a subclass of list (MyList) with an append method, and more importantly also defines 3 proxy classes: ProxyObject, ProxyList and ProxyMyList that are proxy types for object, list and MyList. At the end I try to access methods on instances of a proxy objects for MyList, and finally try to access super(MyList, v).append. That only works when append is in the __dict__ for ProxyList (for example by uncommenting the 3 lines just above the use of super()). -- Added file: http://bugs.python.org/file30528/supers.py ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue18181] super vs. someclass.__getattribute__
Amaury Forgeot d'Arc added the comment: issue783528 was a bit similar. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue18181] super vs. someclass.__getattribute__
Ronald Oussoren added the comment: Looks like it. That issue was closed without a good reason though. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue18181 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
