What way is the best to check an empty list?

[Martin P. Hellwig]

Raymond Hettinger wrote:
> On Mar 25, 7:38 am, srinivasan srinivas <sri_anna... at yahoo.co.in>
> wrote:
>> For ex: to check list 'A' is empty or not..
>> if A == []:
>> if A.count == 0:
>> if len(A) == 0:
>> if not A:
> 
> PEP 8 recommends the latter.
> 
> 
> Raymond
I can't seem to find where this recommendation is mentioned or implied.

Personally I would go for the len version for the sole reason that its 
immediate clear what it is what I am trying to do here. So that when I 
reread my code a couple of weeks later I don't have to think, eh was A a 
bool, oh no I was checking if that list had content in it.

But that could be just me though :-)

YMMV
-- 
mph