unittest vs py.test?

[Roy Smith]

In article <pan.2005.04.04.23.26.28.468507 at jerf.org>,
 Jeremy Bowers <jerf at jerf.org> wrote:

> On Mon, 04 Apr 2005 22:50:35 +0000, John J. Lee wrote:
> > What I don't understand about py.test (and trying it out seems
> > unlikely to answer this) is why it uses the assert statement.
> > unittest used to do that, too, but then it was pointed out that that
> > breaks when python -O is used, so unittest switched to self.assert_
> > &c.  Does py.test have some way around that?
> 
> "Don't use -O because it doesn't do anything significant?"
> 
> Is this an issue in practice? (Honest question.) If -O did something
> interesting I might use it, but I don't think it does. 

The following program produces different output depending on whether you 
run it with -O or not:

try:
    assert 0
    print "I am running with -O"
except AssertionError:
    print "I'm not"