Decorators, Identity functions and execution...

[Carl Banks]

Chance Ginger wrote:
> On Sun, 09 Apr 2006 09:51:18 +0200, Fredrik Lundh wrote:
>
> > Chance Ginger" wrote:
> >
> >> If I define a decorator like:
> >>
> >> def t(x) :
> >> def I(x) : return x
> >> return I
> >
> > ... you get a syntax error.
> >
>
> It isn't a syntax error...I tried it before I posted. In fact
> def t(x) :
> 	def I(x) : return x
> 	return I
>
> is correct.

You've made the unfortunate mistake of indenting it with tabs, which do
not show up on some newsreaders.  I see the tabs in Google; people
using Microsoft Outlook do not.

Always use spaces when posting, and use them in your code as well.
Spaces are the current recommended practice, and in the future tabs
might become illegal.  I'd prefer tabs myself, but it's more important
to respect community standards than to stick to some silly preference
you have.


> Decorators are a way to add "syntactic" sugar to Python,
> extending it in ways that make it useful for tools. What
> I am trying to do is lessen the impact on the time used
> in executing Python code when I use some forms of decorators.

One suggestion.  Have you run the script, determined it's too slow, and
are trying to optimize?  If not (and it doesn't sound like you are), I
suggest that it's too soon to worry about whether this decorator has
any overhead.  You may end up doing a lot of work optimizing that will
ultimately have very little benefit.

Having said that, this decorator will not affect calling overhead at
all.  The decorator is applied when the module is loaded, not when the
decorated function is called.


Carl Banks