Non-deterministic output

[Esben Nielsen]

On Mon, 2011-03-28 at 12:58 +0100, Tim Wintle wrote:
> On Mon, 2011-03-28 at 12:42 +0200, Esben Nielsen wrote:
> > We are making a prototype program in Python. I discovered the output was
> > non-deterministic, i.e. I rerun the program on the same input files and
> > get different output files. We do not use any random calls, nor
> > threading.
> > 
> > One of us thought it could be set and dictionaries not always yielding
> > the same results. I, however, would think that given the exact same
> > operations, a set/dictionary would always yield the same results. Am I
> > correct? Or could different runs of the same program yield different
> > results due to, say, different memory locations?
> 
> If you're using id() at any point (e.g. in __hash__ ) then that would
> lead to non-deterministic behaviour.
> 
I changed my code to use other kinds of hash. That helped! :-) Thanks!

> obviously so would time.time() etc.

I didn't use those :-)
> 
> 

Esben