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From: dn <PythonList@DancesWithMice.info>
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Subject: Re: Configuring an object via a dictionary
Date: Sun, 17 Mar 2024 17:15:32 +1300
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On 17/03/24 12:06, Peter J. Holzer via Python-list wrote:
> On 2024-03-16 08:15:19 +0000, Barry via Python-list wrote:
>>> On 15 Mar 2024, at 19:51, Thomas Passin via Python-list <python-list@python.org> wrote:
>>> I've always like writing using the "or" form and have never gotten bit
>>
>> I, on the other hand, had to fix a production problem that using “or” introducted.
>> I avoid this idiom because it fails on falsy values.
> 
> Perl has a // operator (pronounced "err"), which works like || (or),
> except that it tests whether the left side is defined (not None in
> Python terms) instead of truthy. This still isn't bulletproof but I've
> found it very handy.


So, if starting from:

     def method( self, name=None, ):

  rather than:

     self.name = name if name else default_value

ie

     self.name = name if name is True else default_value


the more precise:

     self.name = name if name is not None or default_value

or:

     self.name = default_value if name is None or name

because "is" checks for identity, whereas "==" and True-thy encompass a 
range of possible alternate values?

-- 
Regards,
=dn