[Python-ideas] [Python-Dev] What's the status of PEP 505: None-aware operators?

Steven D'Aprano steve at pearwood.info
Fri Dec 1 05:37:14 EST 2017


On Thu, Nov 30, 2017 at 08:02:08PM +0300, Ivan Pozdeev via Python-ideas wrote:

> My experience with these operators in C# says:
> * They do save "more than a few keystrokes". Even more importantly, they 
> allow to avoid double evaluation or the need for a temporary variable 
> workaround that are inherent in "<expr> if <expr> else <alternative>"
>     * (An alternative solution for the latter problem would be an 
> assignment expression, another regularly rejected proposal.)
> * They make it temptingly easy and implicit to ignore errors.

How? 

> * They are alien to Python's standard semantics on search failure which 
> is to raise an exception rather than return None

Alien, like this?

py> mo = re.match(r'\d:', 'abc')
py> mo is None
True


Besides, who said this is limited to searching? I don't remember even a 
single example in the PEP being about searching.



-- 
Steve


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