| msg24796 - (view) |
Author: Alexander Kozlovsky (kozlovsky) |
Date: 2005-03-25 21:54 |
| According documentation, proxy in most contexts must have the same behaviour as object itself. PROBLEM: bool(proxy_object) != bool(object_itself) EXAMPLE: >>> class X(list): pass # collection class ... >>> x = X() # empty collection >>> import weakref >>> proxy = weakref.proxy(x) >>> bool(x) False >>> bool(proxy) True PYTHON VERSION: 2.4 (#60, Nov 30 2004, 11:49:19) [MSC v.1310 32 bit (Intel)] also tested on: 2.3.4 (#53, May 25 2004, 21:17:02) [MSC v.1200 32 bit (Intel)] |
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| msg24797 - (view) |
Author: Armin Rigo (arigo) *  |
Date: 2005-03-26 14:50 |
| Logged In: YES user_id=4771 The bug is in weakrefobject:proxy_nonzero(), which calls the underlying object's nb_nonzero slot instead of going through the general PyObject_IsTrue() mecanism. Built-in types like list and dict don't have a nb_nonzero slot. As a related bug, (Callable)ProxyType should implement tp_richcompare in addition to tp_compare. In fact, we should review the code to check if ProxyType knows about the most recent type slots... |
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| msg24798 - (view) |
Author: Raymond Hettinger (rhettinger) * |
Date: 2005-03-27 11:17 |
| Logged In: YES user_id=80475 Fixed the __nonzero__ problem for Py2.5 and will backport to Py2.4. See Objects/weakrefobject.c 1.21. Leaviing this report open until the rest of the module can be checked and fixed. |
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| msg24799 - (view) |
Author: Armin Rigo (arigo) * |
Date: 2005-03-29 13:23 |
| Logged In: YES user_id=4771 The following type slots appear to be missing in the proxy types: * nb_(inplace_){floor,true}_divide * sq_repeat, sq_concat, sq_item, sq_ass_item, sq_inplace_concat, sq_inplace_repeat (which are needed for operator.repeat(), operator.concat(), etc. to work) * tp_as_buffer * tp_richcompare (tp_compare alone is not enough) * tp_descr_get, tp_descr_set (for proxies to descriptors...) * nb_coerce (though it seems that only an explicit call to coerce() can show that this is missing; implicit coercion is done correctly in other operators) * nb_oct, nb_hex As far as I can tell, there is no existing operator that is broken in the same way that nb_nonzero was. |
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| msg24800 - (view) |
Author: Michael Hudson (mwh) |
Date: 2005-03-29 13:39 |
| Logged In: YES user_id=6656 Also see bug #1075356 (which is very minor, but might as well get fixed at the same time). |
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| msg56062 - (view) |
Author: Sean Reifschneider (jafo) * |
Date: 2007-09-20 17:46 |
| Raymond: Is this still a problem, or should we close it because the reported issue is resolved and 2.4 is no longer maintained? |
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| msg114490 - (view) |
Author: Mark Lawrence (BreamoreBoy) * |
Date: 2010-08-21 12:42 |
| I'll close this in a couple of weeks unless anyone objects. |
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| msg114500 - (view) |
Author: Armin Rigo (arigo) * |
Date: 2010-08-21 15:19 |
| All the missing type slots I reported can cause incorrect behavior very similar to the one reported originally. For example (in Python 2.7): class I(int): pass i = I(123) hex(i) => '0x7b' hex(weakref.proxy(i)) => TypeError I think that the present bug report is fine to report these as bugs, as I don't see the point of opening another bug report with the same title. I will just re-mark this issue as "open - not resolved". |
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| msg125272 - (view) |
Author: Antoine Pitrou (pitrou) * |
Date: 2011-01-04 01:23 |
| Works in 2.7 and 3.2. |
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| msg125347 - (view) |
Author: Armin Rigo (arigo) * |
Date: 2011-01-04 18:35 |
| Not for me (the last example I posted, on 2.7 head). But I will not fight for this. |
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