Which is more pythonic?

[Rhodri James]

On Thu, 03 Dec 2009 15:41:56 -0000, Filip Gruszczyński  
<gruszczy at gmail.com> wrote:

> I have just written a very small snippet of code and started thinking,
> which version would be more pythonic. Basically, I am adding a list of
> string to combo box in qt. So, the most obvious way is:
>
> for choice in self.__choices:
> 	choicesBox.addItem(choice)
>
> But I could also do:
>
> map(self.__choices, choicesBox.addItem)
>
> or
>
> [choicesBox.addItem(choice) for choice in self.__choices]
>
> I guess map version would be fastest and explicit for is the slowest
> version.

I vaguely recall someone (Steven?) doing some timings that came up with  
the opposite answer.  The list comprehension is probably the worst  
performing, since it creates a whole new list of the return values of  
choicesBox.addItem(choice), then throws it away.

> However, the first, most obvious way seems most clear to me
> and I don't have to care about speed with adding elements to combo
> box. Still, it's two lines instead of one, so maybe it's not the best.
> So, which one is?

Your instincts are right, the explicit for loop is the more pythonic way  
in this case.  More efficient or not, map() isn't a particularly pythonic  
way to do things, and there's no point using a list comprehension when you  
aren't building a list.

-- 
Rhodri James *-* Wildebeest Herder to the Masses