Re: weblogsping.py error handling patch

Correct me if I'm wrong, but I think the email at that link is talking 
about type checking versus using a try/except block as opposed to using a 
try/except block versus not using one.

What version of Python are you using?  I'm using Python 2.3 on an ibook G4 
(800 mhz) with Mac OS 10.3 and I get:

    10000 took 7.8344 seconds
    10000 took 10.9729 seconds

with the code you posted.  That seems pretty significant to me.  We use 
callbacks in a few places where the runtime is O(n) where n is the number 
of blog entries you have.  If you have several plugins on the same 
callback, then that becomse O(m * n) where m is the number of plugins and 
n is the number of entries, though m is likely < 10.

Does that sound right?

/will


On Tue, 29 Aug 2006, Blake Winton wrote:
> 
> Will wrote:
>> Say you wrapped each cb_ function call in a callback list in
>> a try/except block.  First off, you're incurring a
>> performance decrease because try/except blocks are somewhat
>> expensive.
>
> Really?
>
> http://mail.python.org/pipermail/python-list/2001-May/045621.html
>
> (It seems that it's not the try block that's slow, it's the throwing
> of the exception...)
>
> My experiments confirm this hypothesis...
>
> ----------------------
> import time
>
> def timeIt( func ):
>    start = time.time()
>    for i in xrange( 1000 ):
>        name = func()
>    end = time.time()
>    print '%s took %5.4f seconds'%(name, end - start)
>
> def base():
>    j = 0
>    for i in xrange(10000):
>        j = i+1
>    return j
>
> def tryblock():
>    j = 0
>    for i in xrange(10000):
>        try:
>            j = i + 1
>        except TypeError, e:
>            pass
>    return j
>
> timeIt( base )
> timeIt( tryblock )
> ----------------------
> (From the above code)
> 10000 took 1.2830 seconds
> 10000 took 1.7450 seconds
> ----------------------
> (From another run, of 10 times as many tests...)
> 10000 took 9.5540 seconds
> 10000 took 13.6610 seconds
> ----------------------
>
> So, ya know, for 10,000,000 try blocks, it took 0.462 seconds.
> Not all that expensive, I don't think...
>
> Later,
> Blake.

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