None???

[David Eppstein]

In article <4l4umv4kl82d8t5td29in26cfb57ctb6h0 at 4ax.com>,
 Tim Rowe <tim at remove_if_not_spam.digitig.co.uk> wrote:

> >Arguably, any code that uses / with integer arguments is now buggy, 
> >because it will produce different results in different Python versions.  
> >You should either use // (integer division) or force floating point 
> >division (e.g. by changing the expression to income*percent/100.0).
> 
> What's the behaviour of "from __future__ import division" on versions
> that are too old to know about the future of division?

A nice error message.
So that's another good way to go.

-- 
David Eppstein                      http://www.ics.uci.edu/~eppstein/
Univ. of California, Irvine, School of Information & Computer Science