Re: [Webware-discuss] Private _variables

[Tavis R. <ta...@ca...>]

On Saturday 12 January 2002 08:36, Tim Payne wrote:
> On Saturday, January 12, 2002, at 10:37  AM, Mike Orr wrote:
> > <snip>
>
> Thanks Mike (and Frank).  You both cleared up some
> misunderstandings I had about the way python dealt with
> variables/attributes.
>
> Since you guys brought it up, I was also wondering why WebKit uses
> this style of importing (from module import object) over (import
> module)
>
> I know that when you import the object(s) directly, you can use
> them like foo() instead of module.foo(), but is there any other
> advantage? I usually just import the module so that I don't get
> confused about where everything is being loaded from.

In addition to what Mike said, it can be much faster at run time to 
use variables without lots of dots in them.  This can make a huge 
performance difference in loops, and WebKit's request/response cycle 
is conceptually a big loop.

SLOW:
-----
import os.path
def foo():
    os.path.join(...) 

FASTER (but harder to follow in a large file):
-----------------------------------------------
from os.path import join
def foo():
    join(...) 

FASTEST (my preferred style):
--------
import os.path
def foo(join=os.path.join):
    join(...) 


Tavis