cascading python executions only if return code is 0

[Roy Smith]

In article <52bd049d$0$29992$c3e8da3$5496439d at news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> Roy Smith wrote:
> 
> > In article <mailman.4567.1387819120.18130.python-list at python.org>,
> >  Ethan Furman <ethan at stoneleaf.us> wrote:
> > 
> >> Mostly I don't want newbies thinking "Hey!  I can use assertions for all
> >> my confidence testing!"
> > 
> > How about this one, that I wrote yesterday;
> > 
> >         assert second >= self.current_second, "time went backwards"
> > 
> > I think that's pretty high up on the "can never happen" list.
> 
> Time goes backwards by one hour[1] at least once a year across most of the
> world. 

Only if you're stupid enough to run your systems in local time.

> http://infiniteundo.com/post/25509354022/more-falsehoods-programmers-believe-a
> bout-time-wisdom

Most of those deal with things like daylight saving time and time zones 
and calendars, which are all far more complicated (and chaotic) than 
just keeping track of UTC timestamps.

There's lists like that for names and genders too.  As in, what do you 
mean there are people who don't have exactly two names and one gender?