On 12/17/2012 4:14 AM, Ian Kelly wrote:
On Sun, Dec 16, 2012 at 9:30 PM, Nick M. Daly <nick.m.d...@gmail.com> wrote:
It's very unlikely that multiple inheritance would go horribly wrong, as
long as classes adopt class-specific argument naming conventions.
However, ever since bug 1683368 [0] was fixed, it's now impossible to
cleanly create arbitrary inheritance trees.
No, it isn't. You just code each class to strip out the particular
arguments that it uses, and by the time you get up to object, either
you've removed all the arguments, or your inheritance tree is buggy.
The fix for bug 1683368 means that this latter case is detected and
raised as an error.
In other words, one could say that the fix forces a clean inheritance tree.
There was a thread not too long ago about the fact that this fix was
recently extended to the __init__ methods of immutable classes,
Since 3.3.0?
>>> object.__init__(object(), 1)
Traceback (most recent call last):
File "<pyshell#4>", line 1, in <module>
object.__init__(object(), 1)
TypeError: object.__init__() takes no parameters
>>> tuple.__init__(tuple(), 1)
>>>
Or were you referring to something else? Or done since?
while I'm not convinced that this was the correct thing to do, Terry
Reedy pointed out in the issue comments back in 2010 that the proper
way to initialize immutable instances is by overriding __new__ rather
than __init__, the former of which is still perfectly clean to
inherit.
It seems to me that tuple, etc., should just inherit __init__ from object.
--
Terry Jan Reedy
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