A.T.Hofkamp wrote:
> 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?)
As Bruno says, this will change in 3.0:
# 3.0
>>> class A: pass
...
>>> min(1.0, A())
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: unorderable types: A() < float()
For 2.5 and above you can provide a key function as a workaround:
# 2.5
>>> class A(object): pass
...
>>> min(1, A(), key=float)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: float() argument must be a string or a number
Peter
--
http://mail.python.org/mailman/listinfo/python-list
