On Tue, Sep 28, 2010, Lie Ryan wrote: >On 09/28/10 13:57, Bill Allen wrote: >> I can now see that quite a bit of the code I write dealing with lists >> can be done with list >> comprehensions. My question is this, is the list comprehension styled >> code generally >> more efficient at runtime? If so, why? > >Yes, because the looping in list comprehension is done in C instead of a >python construct. However, they are the type of efficiency that you >shouldn't bother yourself with unless you're microoptimizing.
True enough, but dealing with large lists can be expensive, particularly when appending. Before I discovered sets, I found significant time savings by creating a dictionary, adding as necessary, then use d.keys() to get the keys back. This became a significant factor when I was selecting unique lines from about 1.3 million samples. Bill -- INTERNET: b...@celestial.com Bill Campbell; Celestial Software LLC URL: http://www.celestial.com/ PO Box 820; 6641 E. Mercer Way Voice: (206) 236-1676 Mercer Island, WA 98040-0820 Fax: (206) 232-9186 Skype: jwccsllc (206) 855-5792 Independent self-reliant people would be a counterproductive anachronism in the collective society of the future where people will be defined by their associations. 1896 John Dewey, educational philosopher, proponent of modern public schools. _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
