Hi, A friend of mine stumbled upon the following behavior: ---cut---
class A(object): pass ... class B(object): ... def __add__(self, other): ... print 'B: adding B and %s objects.' % other.__class__.__name__ ... class C(object): ... def __radd__(self, other): ... print 'C: adding C and %s objects.' % other.__class__.__name__ ... a, b, c = A(), B(), C()
b + c B: adding B and C objects.
a + c C: adding C and A objects.
# so far, quite logical. now let's do this:
1 + c C: adding C and int objects.
--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. -- Alex.