code review

Thomas Jollans t at jollybox.de
Mon Jul 2 16:26:02 CEST 2012


On 07/02/2012 02:43 AM, Steven D'Aprano wrote:
> On Sun, 01 Jul 2012 09:35:40 +0200, Thomas Jollans wrote:
>> This is simply wrong. The comparisons are not acting as binary
>> operators.
> 
> Of course they are. Take this chained comparison:

Technically, yes - two-input operations are happening. Syntactically,
no. Read my post.

> 1) What is the operator in this expression? Is it < or == or something 
> else?

I think I've answered this - it's the combination.

> 2) What double-underscore special method does it call? Where is this 
> mysterious, secret, undocumented method implemented?
> 
> 3) Why do the Python docs lie that a < b == c is exactly equivalent to 
> the short-circuit expression (a < b) and (b == c) with b evaluated once?
> 
> 4) And how do you explain that the compiled byte code actually calls the 
> regular two-argument binary operators instead of your imaginary three-
> argument ternary operator?

In this context, I don't care what actually happens. I'm talking about
how the code can be parsed (by the generic reader, not necessarily the
python interpreter).





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