Comments on: Sort one list by another list http://scienceoss.com/sort-one-list-by-another-list/ useful tidbits for using open source software in science Thu, 20 Nov 2008 16:48:22 +0000 http://wordpress.org/?v=2.6 By: ryan http://scienceoss.com/sort-one-list-by-another-list/#comment-34 ryan Mon, 14 Apr 2008 20:22:03 +0000 http://scienceoss.com/sort-one-list-by-another-list/#comment-34 Inspired by Andrew I learned some more about using a key function to sort by. My notes are here: http://scienceoss.com/advanced-sorting-sorting-by-key/ Inspired by Andrew I learned some more about using a key function to sort by. My notes are here: http://scienceoss.com/advanced-sorting-sorting-by-key/

]]> By: ryan http://scienceoss.com/sort-one-list-by-another-list/#comment-27 ryan Sun, 13 Apr 2008 17:03:06 +0000 http://scienceoss.com/sort-one-list-by-another-list/#comment-27 @Matt: You got me thinking about whether or not the first way is best. Turns out sometimes the first method is best . . . but sometimes it's not. For more: http://scienceoss.com/test-the-speed-of-your-code-interactively-in-ipython/. @Andrew Perry: Good call on using the key function to sort by. Now that I think about it, it might be worth a separate post with some more examples of using "sort(key=someFunc)". Stay tuned. @Matt:
You got me thinking about whether or not the first way is best. Turns out sometimes the first method is best . . . but sometimes it’s not. For more: http://scienceoss.com/test-the-speed-of-your-code-interactively-in-ipython/.

@Andrew Perry:
Good call on using the key function to sort by. Now that I think about it, it might be worth a separate post with some more examples of using “sort(key=someFunc)”. Stay tuned.

]]> By: Andrew Perry http://scienceoss.com/sort-one-list-by-another-list/#comment-25 Andrew Perry Sun, 13 Apr 2008 01:49:59 +0000 http://scienceoss.com/sort-one-list-by-another-list/#comment-25 Thanks, nice quick tutorial. I've really got to use Numpy more often, I'm sure it would make my life easier. Just playing with the examples ... here's how to sort the list alphabetically by "people" rather than by age (for Method 1). Change the .sort() line to: agesAndPeople.sort(key=lambda x: x[1]) The key argument can be passed any function which when passed any element of the list being sorted, returns a value to actually sort on. In this case, the key function is a quick on-the-fly lamba function which returns the second element of the tuple (rather than defaulting to the first element, as in Method 1 above), in effect sorting on the peoples names rather than the age. Thanks, nice quick tutorial. I’ve really got to use Numpy more often, I’m sure it would make my life easier.

Just playing with the examples … here’s how to sort the list alphabetically by “people” rather than by age (for Method 1). Change the .sort() line to:

agesAndPeople.sort(key=lambda x: x[1])

The key argument can be passed any function which when passed any element of the list being sorted, returns a value to actually sort on. In this case, the key function is a quick on-the-fly lamba function which returns the second element of the tuple (rather than defaulting to the first element, as in Method 1 above), in effect sorting on the peoples names rather than the age.

]]> By: Matt http://scienceoss.com/sort-one-list-by-another-list/#comment-18 Matt Fri, 11 Apr 2008 21:42:11 +0000 http://scienceoss.com/sort-one-list-by-another-list/#comment-18 How isn't the first way the best? How isn’t the first way the best?

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