cascading python executions only if return code is 0

[Chris Angelico]

On Mon, Dec 23, 2013 at 2:10 PM, Dennis Lee Bieber
<wlfraed at ix.netcom.com> wrote:
>         Having spent 22 years with VMS, 0 -> success is still a problem to me.
> Odd result codes (aka True) were 1-success/3-information, even results
> (False) were 0-warning/2-error/4-fatal

Having spent a similar amount of time with Unix, C, and various APIs,
I'm quite used to 0 meaning success and nonzero meaning error.

ChrisA