[docs] [issue13574] refresh example in doc for Extending and Embedding

[Florent Xicluna]

New submission from Florent Xicluna <florent.xicluna at gmail.com>:

The example uses PyInstanceObject which is Python 2 only (old-style classes).

http://docs.python.org/dev/extending/newtypes.html#weak-reference-support

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assignee: docs at python
components: Documentation, Extension Modules
messages: 149183
nosy: docs at python, flox
priority: normal
severity: normal
stage: needs patch
status: open
title: refresh example in doc for Extending and Embedding
type: behavior
versions: Python 3.2, Python 3.3

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue13574>
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