TypeError: multiple bases have instance lay-out conflict
jeremy at alum.mit.edu
Mon Aug 19 15:26:56 CEST 2002
"robin and jim" <robinjim at earthlink.net> wrote in message news:<4GQ79.11079$LO1.881271 at newsread2.prod.itd.earthlink.net>...
> The following 2 class definitions:
> class Spam(object):
> __slots__ = ['notes']
> class Eggs(Spam, dict):
> produce the following error concerning class Eggs:
> TypeError: multiple bases have instance lay-out conflict
> Could someone explain this error message and why the above Eggs class
> definition is prohibited.
The builtin type dict and a new-style class with slots both define
custom object layouts at the C level. The C layout of Spam has a
specific slot for the notes attribute, while the dict type has its
hashtable. There's not way to resolve this conflict, because the
layout of the C structs is fixed for each type.
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