Performance of lists vs. list comprehensions
steve at REMOVE-THIS-cybersource.com.au
Wed Jan 20 02:52:41 CET 2010
On Tue, 19 Jan 2010 11:26:43 -0500, Gerald Britton wrote:
> Interestingly, I scaled it up to a million list items with more or less
> the same results.
A million items is not a lot of data. Depending on the size of each
object, that might be as little as 4 MB of data:
>>> L = ['' for _ in xrange(10**6)]
Try generating a billion items, or even a hundred million, and see how
This is a good lesson in the dangers of premature optimization. I can't
think how many times I've written code using a generator expression
passed to join, thinking that would surely be faster than using a list
comprehension ("save building a temporary list first").
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