New submission from Richard Oudkerk <shibt...@gmail.com>:

In the documentation on weakrefs there is the following quote

    Note: Weak references to an object are cleared before the object’s
    __del__() is called, to ensure that the weak reference callback 
    (if any) finds the object still alive.

But I think the weakref is always dead by the time the callback is invoked.  
The first paragraph from the documentation for weakref.ref(object[, callback]) 
contains the following:

    If callback is provided and not None, and the returned weakref 
    object is still alive, the callback will be called when the object 
    is about to be finalized; the weak reference object will be passed 
    as the only parameter to the callback; **the referent will no longer 
    be available**.

Which does prompt a question: what use is there for the weakref argument to the 
callback if it already dead?

(Compare http://bugs.python.org/issue14933)

----------
assignee: docs@python
components: Documentation
messages: 166002
nosy: docs@python, pitrou, sbt
priority: normal
severity: normal
status: open
title: Note in documentation for weakrefs

_______________________________________
Python tracker <rep...@bugs.python.org>
<http://bugs.python.org/issue15412>
_______________________________________
_______________________________________________
Python-bugs-list mailing list
Unsubscribe: 
http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

Reply via email to