[Python-ideas] Accessing the result of comprehension's expression from the conditional
Georg Brandl
g.brandl at gmx.net
Sat Jun 20 22:00:42 CEST 2009
Lie Ryan schrieb:
> Terry Reedy wrote:
>> Steven D'Aprano wrote:
>>> On Sat, 20 Jun 2009 08:31:26 am Lie Ryan wrote:
>>
>>> You don't like lambda? Fine, define an external function first. Then
>>> you can write:
>>>
>>> filter(pred, (f(x) for x in seq))
>>>
>>> There's no violation of DRY, there's no redundancy, there's no lambda,
>>> there's no "y" variable needed. What's ugly about it?
>>
>> I think its great and that it kills any justification for the proposal.
>>
>> tjr
>
> I hate it. It mixes map/filter style and comprehension style; and the
> fact it does so in a single line only makes it worse. Not that it would
> be any better in two lines.
Taking this further, using only map/filter style like this
filter(pred, map(f, seq))
takes two steps. Why is it so bad that doing it in a listcomp
(el for el in (f(y) for y in seq) if el > 2)
takes two steps as well?
Georg
--
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Four shall be the number of spaces thou shalt indent, and the number of thy
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