Curious about library inclusion

[Rhodri James]

On 15/10/2019 12:38, Antoon Pardon wrote:
> On 11/10/19 15:48, Rhodri James wrote:
>> On 10/10/2019 12:40, Antoon Pardon wrote:
>>> About including piped iterators:
>>>      
>>> http://code.activestate.com/recipes/580625-collection-pipeline-in-python/
>>>
>>> On 10/10/19 13:00, Paul Moore wrote:
>>>> As another measure, look at various other libraries on PyPI and ask
>>>> yourself why *this* library needs to be in the stdlib more than those
>>>> others. The answer to that question would be a good start for an
>>>> argument to include the library.
>>>
>>> Well my answer would be that this library wouldn't add functionality
>>> but rather would allow IMO for a more readable coding style.
>>>
>>> If you split the work to be done over mulitple generators I find it
>>> easier to understand when I read something like:
>>>
>>>       for item in some_file | gen1 | gen2 | gen3:
>>>           ...
>>>
>>> than when I read something like:
>>>
>>>       for item in gen3(gen2(gen1(somefile))):
>>>           ...
>>
>> With my ever-so-reactionary hat on, I have to say I'm the other way
>> round.  With "gen3(gen2(gen1(somefile)))" it's pretty obvious what's
>> going on -- nested function or generator calls, probably the latter
>> from the name.  With "somefile|gen1|gen2|gen3" I need more context to
>> kick my expectations out of the more common meaning of "|" as "or".
>>
>> Yes, context demands that the "|" in your first example can't actually
>> be an "or".  It still causes a moment of logical disconnect (currently
>> a long moment) that throws me out of understanding what your code is
>> doing overall into what this line means in particular.  It's exactly
>> like coming across an unusual phrasing or iffy grammar in a piece of
>> writing; you get thrown out of the reading experience by having to
>> concentrate on the individual words.
> 
> But isn't this just a matter of experience? For example does it still
> causes a moment of logical disconnect when you see a '+' used for
> concatenation? For me the use of '|' is very similar to how it is used
> by unix shells. Would the use of an other operator ease this disconnect
> for you, maybe '>>', or wouldn't that make a difference?

I *could* get used to any syntax, but why should I?  We have syntax that 
works perfectly well already.  Making me go to the extra effort of 
importing shell-style pipes or C++-style streams into my mental 
construct of Python doesn't really seem necessary.

(As it happens, I don't think the use of "+" for concatenation did cause 
me a moment of disconnection, because it already fitted into my mental 
model.  I do recall that's Perl's choice of "." as the concatenation 
operator *did* cause me to stop and reevaluate quite a lot.  People are 
weird :-)

-- 
Rhodri James *-* Kynesim Ltd