Sort list of list python

Question

I have an output like this:

[['ca'], 0.62]
[['ca', 'tf'], 0.62]
[['ca', 'tf', 'se'], 0.71]
[['ca', 'tf', 'se', 'zz'], 0.71]
[['ca', 'tf', 'se', 'zz', 'rd'], 0.42]
[['ca', 'tf', 'se', 'zz', 'rd', 'fbs'], 0.12]
[['ca', 'tf', 'se', 'zz', 'rd', 'fbs', 'th'], 0.56]
[['ca', 'tf', 'se', 'zz', 'rd', 'fbs', 'th', 'ex'], 0.56]

The numbers in the right represent a score, I would like to sort them so I could have it that way:

[['ca', 'tf', 'se'], 0.71]
[['ca', 'tf', 'se', 'zz'], 0.71]
[['ca'], 0.62]
[['ca', 'tf'], 0.62]
[['ca', 'tf', 'se', 'zz', 'rd', 'fbs', 'th'], 0.56]
[['ca', 'tf', 'se', 'zz', 'rd', 'fbs', 'th', 'ex'], 0.56]
[['ca', 'tf', 'se', 'zz', 'rd'], 0.42]
[['ca', 'tf', 'se', 'zz', 'rd', 'fbs'], 0.12]

Higher score with less features first. I used this command:

li.sort(reverse=True)

but I got this error:

TypeError: '<' not supported between instances of 'list' and 'float'

Any idea how to do this properly ?

=====

Edit from Joe Ferndz

@DNZ, please consider this as your input:

li = [[['ca'], 0.62],
[['ca', 'tf'], 0.62],
[['ca', 'tf', 'se'], 0.71],
[['ca', 'tf', 'se', 'zz'], 0.71],
[['ca', 'tf', 'se', 'zz', 'rd'], 0.42],
[['ca', 'tf', 'se', 'zz', 'rd', 'fbs'], 0.12],
[['ca', 'tf', 'se', 'zz', 'rd', 'fbs', 'th'], 0.56],
[['ca', 'tf', 'se', 'zz', 'rd', 'fbs', 'th', 'ex'], 0.56]]

And the solution for this has already been posted by @Ali Shanoon. That should solve for it.

Based on the error message, it looks like you're trying to sort the list `[['ca'], 0.62]`. Are you sure you're sorting the list of scores, not just the first highscore? — Silvio Mayolo, Feb 19 '21 at 21:08
Adding to that, it looks like the code in your first block is equivalent to `li = [['ca'], 0.62]`. — Brian McCutchon, Feb 19 '21 at 21:10
Are you sure `li` is defined correctly? Are you missing commas at the end of `[['ca'], 0.62]` — Joe Ferndz, Feb 19 '21 at 21:10
@SilvioMayolo What I want basically is just the first high score, I was trying to sort the lists reversely so I could select just the first high score. — DNZ, Feb 19 '21 at 21:11
@JoeFerndz, That's the point, the output is like this, no commas after the list. — DNZ, Feb 19 '21 at 21:12
@DNZ, i am not talking about the output. I am talking about the input. I think it is missing a comma and also missing a `[]` at the outside. — Joe Ferndz, Feb 19 '21 at 21:13
Here's a more general answer to this question: https://stackoverflow.com/questions/4233476/sort-a-list-by-multiple-attributes — Brian McCutchon, Feb 19 '21 at 21:24

Ali Shannon · Answer 1 · 2021-02-19T21:22:51.020

2

You were close. Sorted can take a key.

sorted(li, reverse=True, key=lambda x: (x[-1], -len(x[0])))

edited Feb 19 '21 at 21:22

answered Feb 19 '21 at 21:11

Ali Shannon

186
3

Sort list of list python

Edit from Joe Ferndz

1 Answers1