the annoying, verbose self

[Colin J. Williams]

Steven D'Aprano wrote:
> On Fri, 23 Nov 2007 23:38:24 +0000, BJörn Lindqvist
> wrote:
> 
>> I like that a lot. This saves 12 characters for the original example and
>> removes the need to wrap it.
>>
>> 7            return math.sqrt(.x * .x + .y * .y + .z * .z)
>>
>> +1 Readability counts, even on small screens.
> 
> -2 Readability counts, and your example is a lot less readable.
> 
> For your example to be even *slightly* readable, you have to fill the 
> expression with excessive whitespace. A little bit of whitespace is good. 
> Too much breaks the flow of the expression and hurts readability.
> 
> Or perhaps I should say:
> 
> T o o   m u c h   b r e a k s   t h e   f l o w . . . 
> 
> 
> You write: math.sqrt(.x * .x + .y * .y + .z * .z)
> 
> which to my eyes has too much whitespace, but the alternative is worse:
> math.sqrt(.x*.x + .y*.y + .z*.z)
> 
> and this is positively painful to try to read, it looks like line-noise:
> math.sqrt(.x*.x+.y*.y+.z*.z)
> 
> 
> 
> The correct solution to your example is to get rid of the attribute 
> lookups from the expression completely:
> 
> 
> def abs(self):
>     x, y, z = self.x, self.y, self.z
>     return math.sqrt(x**2 + y**2 + z**2)
> 
> 
> It's probably also faster, because it looks up the attributes only once 
> each, instead of twice.
> 
> 
Alternatively, as someone else 
suggested, an analogue of the Pascal "with"
could be used:

def abs(self):
   with self:
     return math.sqrt(x**2 + y**2 + z**2)

As has already been pointed out, "with" 
has been pre-empted (unfortunately,
in my view) for another purpose.

This form could be generalized to "with 
aa" where aa is any object with
attributes accessible with the z= aa.z 
or aa.z.= z style.

This should not apply to special names, 
such as __add__ etc.

Colin W.
>