On 19/03/2010 12:46, Alex A. Naanou wrote:
[snip...]
class C(object):
... def __radd__(self, other):
... print 'C: adding C and %s objects.' % other.__class__.__name__
...
a, b, c = A(), B(), C()
1 + c
C: adding C and int objects.
That is the whole point of the __radd__ method. ints don't know how to
add themselves to C objects, so int.__add__ will return NotImplemented
and then Python will try C.__radd__.
All the best,
Michael
--uncut--
My first expectation would be to get a TypeError here, as ints indeed
have an __add__ method, and they do not know anything about C objects
(obviously :) ). On second thought, giving client code priority to
handle things has it's merits.
The problem is that I found no mention of this behavior in the docs.
P.S. tested in 2.5 through 3.0 and PyPy
Thanks.
--
http://www.ironpythoninaction.com/
http://www.voidspace.org.uk/blog
READ CAREFULLY. By accepting and reading this email you agree, on behalf of
your employer, to release me from all obligations and waivers arising from any
and all NON-NEGOTIATED agreements, licenses, terms-of-service, shrinkwrap,
clickwrap, browsewrap, confidentiality, non-disclosure, non-compete and
acceptable use policies (”BOGUS AGREEMENTS”) that I have entered into with your
employer, its partners, licensors, agents and assigns, in perpetuity, without
prejudice to my ongoing rights and privileges. You further represent that you
have the authority to release me from any BOGUS AGREEMENTS on behalf of your
employer.
_______________________________________________
Python-Dev mailing list
Python-Dev@python.org
http://mail.python.org/mailman/listinfo/python-dev
Unsubscribe:
http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com