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Author serhiy.storchaka
Recipients serhiy.storchaka
Date 2015-10-16.16:41:58
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Default __sizeof__() implementation uses tp_basicsize. This makes it to work correctly with most builtin types and types with __slots__ (using __slots__ increases tp_basicsize). But special implementations of __sizeof__() use static object size ('sizeof(XXXObject)'), and return incorrect result for subclasses that increase tp_basicsize. Proposed patch makes __sizeof__() for all subclassable builtin type that support changing object size (i.e. tp_itemsize == 0) to use dynamic size _PyObject_SIZE(Py_TYPE(self)).

Example (with patched code):
>>> class D(dict):
...     __slots__ = 'a', 'b', 'c'
>>> sys.getsizeof({})
>>> sys.getsizeof(D())

In unpatched Python sys.getsizeof(D()) returns 144.
Date User Action Args
2015-10-16 16:42:01serhiy.storchakasetrecipients: + serhiy.storchaka
2015-10-16 16:42:00serhiy.storchakasetmessageid: <>
2015-10-16 16:42:00serhiy.storchakalinkissue25421 messages
2015-10-16 16:42:00serhiy.storchakacreate