Speed ain't bad

Bulba! bulba at bulba.com
Sun Jan 2 19:39:30 CET 2005


On Sat, 1 Jan 2005 14:20:06 +0100, "Anders J. Munch"
<andersjm at inbound.dk> wrote:

>> One of the posters inspired me to do profiling on my newbie script
>> (pasted below). After measurements I have found that the speed
>> of Python, at least in the area where my script works, is surprisingly
>> high.
>
>Pretty good code for someone who calls himself a newbie.

<blush>

>One line that puzzles me:
>>     sfile=open(sfpath,'rb')

>You never use sfile again.

Right! It's a leftover from a previous implementation (that
used bzip2). Forgot to delete it, thanks.

>Another way is the strategy of "it's easier to ask forgiveness than to
>ask permission".
>If you replace:
>    if(not os.path.isdir(zfdir)):
>        os.makedirs(zfdir)
>with:
>    try:
>        os.makedirs(zfdir)
>    except EnvironmentError:
>        pass

>then not only will your script become a micron more robust, but
>assuming zfdir typically does not exist, you will have saved the call
>to os.path.isdir.

Yes, this is the kind of habit that low-level languages like C 
missing features like exceptions ingrain in a mind of a programmer...

Getting out of this straitjacket is kind of hard - it would not cross
my mind to try smth like what you showed me, thanks!

Exceptions in Python are a GODSEND. I strongly recommend
to any former C programmer wanting to get rid of a "straightjacket"
to read the following to get an idea how not to write C code in Python
and instead exploit the better side of VHLL:

http://gnosis.cx/TPiP/appendix_a.txt




--
It's a man's life in a Python Programming Association.



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