default object comparison considered harmful?

[Bruno Desthuilliers]

A.T.Hofkamp a écrit :
> Hello all,
> 
> Yesterday we found the cause of a bug that has caused problems for a long time.
> It appeared to be the following:
> 
> class A(object):
>     pass
> 
> print min(1.0, A())
> 
> which is accepted by Python even though the A() object is not numerical in
> nature.
> 
> The cause of this behavior seems to be the compare operation of the object
> class.
> 
> 
> Is there a way to disable this behavior in Python (other than deriving a new
> 'object-like' class that doesn't do comparisons?)

Other than implementing a custom __cmp__ function ? Not AFAIK. FWIW, you 
don't necessarily need to fiddle with inheritance - you can also 
monkeypatch your classes (nb : for new-style objects, you cannot 
monkeypatch __magic__ methods on a per-object basis).

Also, IIRC, this behaviour has changed in Python 3.