For those interested in this topic, if you are not already aware of it,
see also http://bugs.python.org/issue25958, which among other things
has a relevant proposed patch for datamode.rst.
On Tue, 07 Jun 2016 10:56:37 -0700, Guido van Rossum wrote:
> Setting it to None in the subclass is the inte
Setting it to None in the subclass is the intended pattern. But CPython
must explicitly handle that somewhere so I don't know how general it is
supported. Try defining a list subclass with __len__ set to None and see
what happens. Then try the same with MutableSequence.
On Tue, Jun 7, 2016 at 10:3
> From: Ethan Furman
> Sent: Tuesday, June 07, 2016 1:38 PM
> To: Python Dev
> Subject: [Python-Dev] Proper way to specify that a method is not defined
for
> a type
(Just so everyone follows, this is a followup of
http://bugs.python.org/issue27242 )
> For binary methods, such
For binary methods, such as __add__, either do not implement or return
NotImplemented if the other operand/class is not supported.
For non-binary methods, simply do not define.
Except for subclasses when the super-class defines __hash__ and the
subclass is not hashable -- then set __hash__ to
