PEP 308: Pep Update

Steven Taschuk staschuk at telusplanet.net
Thu Feb 27 20:21:52 CET 2003


Quoth I:
  [...]
> I prefer that expressions appear, left-to-right, in the order they
> are evaluated.  [...]
> (List comprehensions are a notable counterprecedent.)

... which, I now realize, suggests the alternative
	y but x if C
Note that the second expression, not the first, is evaluated if C
is true.  (This is very like the unseconded option III.3 in
Francis's list of proposals <3E52F313.4B917E50 at alcyone.com>,
except that is uses 'but' instead of 'or'.)

Chained uses such as
	t = z but y if D but x if C
do not read quite as naturally, sadly.  It's not even clear what
the result of this should be if C and D are both true.  Mandatory
parentheses might help.

-- 
Steven Taschuk                            staschuk at telusplanet.net
Every public frenzy produces legislation purporting to address it.
                                           (Kinsley's Law)





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