Mel Wilson wrote:
In article <[EMAIL PROTECTED]>, Steven Bethard <[EMAIL PROTECTED]> wrote:
I believe what Peter Otten was pointing out is that calling __eq__ is not the same as using ==, presumably because the code for == checks the types of the two objects and returns False if they're different before the __eq__ code ever gets called.
Doesn't seem to:
[snip]
Check his example:
http://mail.python.org/pipermail/python-list/2004-November/252660.html
I suspect that example is due to the rule that "A op B" can be passed to any of the following, depending on the operator and the types of A and B:
A.__op__(B) B.__op__(A) B.__rop__(A)
The latter two get invoked when B is a proper subclass of A (using 'op' for commutative operations, and 'rop' for potentially non-commutative ones). This is so that subclasses can interact with parent classes correctly.
So, in Steven's original code, B.__eq__(A) was invoked, and returned False (since A was the parent class of B, not a subclass).
Cheers, Nick. -- http://mail.python.org/mailman/listinfo/python-list
