Nebie: list question, speed
rickp at telocity.com
Sat May 5 17:18:08 EDT 2001
On Sat, 5 May 2001 17:30:59 +0200 in comp.lang.python, Werner Hoch wrote:
> I wrote a little programm parsing two textfiles together.
> The result is a list without uniq entries:
> So i wrote this to check if the entry already exists:
> if ergfield.count(ergline) == 0:
> execution time is about 45 seconds
This *always* looks at *every* element in ergfield.
> an then I tried a second statment which is twice as fast as the first one:
> execution time is about 21 seconds
This stops looking as soon as it finds a match.
The execution time will vary depending on the order of the input data.
> I don't like the second solution because it uses the exeption handling like
> a if statement!
> Are there better ways to do this?
Nothing wrong with using try/except.
Using 'if ergline not in ergfield' instead of 'ergfield.count' should
give closer to the same timings as your try/except.
"Censorship, like charity, should begin at home, but unlike charity,
it should end there."
-- Clare Boothe Luce
Rick Pasotto email: rickp at telocity.com
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