[Python-ideas] About list comprehension syntax

[Boris Borcic]

Terry Reedy wrote:
> "Arnaud Delobelle" 
...
> |  Thus (3) could be written more simply as:
> |
> | (3') [x in L if p(x)]
> 
> (x in L) is a legal expression already.  

That's the only real issue IMO - and I agree there is no acceptable solution.

> (x in L) if p(x) looks like the 
> beginning of (x in L) if p(x) else 'blah' .  The whole thing looks like a 
> list literal with an incompletely specified one element.
> 
> | This is consistent with common mathematical notation:
> 
> 'Common mathematical notation' is not codified and varies from writer to 
> writer and even within the work of one writer.  Humans make do and make 
> guesses, but parser programs are less flexible.

I guess it also depends on how much math (eg theorem proofs) one had to deal 
with. FWIW, it took me months to adapt to the correct Python listcomp/genexp 
syntax, after being bitten dozens of times by Python not accepting Arnaud's (3') 
form above. The latter was *much* more natural to my fingers.

Cheers, BB