Comparisons of incompatible types

[Carl Banks]

On Dec 6, 4:17 pm, Steven D'Aprano <steve
+comp.lang.pyt... at pearwood.info> wrote:
> On Mon, 06 Dec 2010 08:59:12 -0800, TomF wrote:
> > I'm aggravated by this behavior in python:
>
> > x = "4"
> > print x < 7    # prints False
> > I can't imagine why this design decision was made.
>
> You've never needed to deal with an heterogeneous list?
>
> data = ["Fred", "Barney", 2, 1, None]
> data.sort()

Not once, ever.


> Nevertheless, I agree that in hindsight, the ability to sort such lists
> is not as important as the consistency of comparisons.

I think that feeling the need to sort non-homogenous lists is
indictative of bad design.

If the order of the items doesn't matter, then there must be some
small bit of homogeneity to exploit to use as a sort criterion.  In
that case you should use key= parameter or DSU.


Carl Banks