random.choices() Suggest that the code confirm that cum_weights sequence is in ascending order

Mon May 14 07:36:04 EDT 2018

Hi Paul, and welcome!

On Sun, 13 May 2018 17:48:47 -0700, Paul wrote:

> Hi,
>   I just learned how to use random.choices().  
[...]
> Consequently, I specified 'cum_weights' with a sequence which wasn't in
> ascending order.  I got back k results but I determined that they
> weren't correct (eg, certain population values were never returned).
> 
>   Since the non-ascending sequence, which I had supplied, could not
> possibly be valid input, why isn't this checked (and an error returned)?
>  Returning incorrect results (which could be hard to spot as being
> incorrect) is much more dangerous.  Also, checking that the list is in
> ascending order need only be done once, and seems like it would be
> inexpensive.

Sounds like a reasonable feature request to me.

https://bugs.python.org/issue33494

-- 
Steve