Misuse of list comprehensions?

[Diez B. Roggisch]

Thomas Bellman wrote:

> "Diez B. Roggisch" <deets at nospam.web.de> writes:
> 
>> bearophileHUGS at lycos.com wrote:
> 
>>> The Example 2 builds a list, that is then thrown away. It's just a
>>> waste of memory (and time).
> 
>> No, it doesn't. It uses append because it refers to itself in the
>> if-expression. So the append(c) is needed - and thus the assignment
>> possible but essentially useless.
> 
> Yes it does.  A list comprehension *always* creates a list.  In
> this case it will be a list of None, since that is what list.append()
> returns.  See this:

Yep - no idea how that slipped me. I still don't mind the occasional waste
of a list-creation over a more concise looping-construct, but I totally
admit that one has to be aware of this. more than I was....

Diez