How can I specify key argument in sort() function however complex the argument be?

Question

I have a nested list having elements of format ['name',float_val].

Nlist = [['naveen',31.5],['murali',44.1],['sai',23.1],['satya',23.1]]

I want to sort the above nested list by float object. How should I specify the 'key' argument in sort() function to fulfill my need?

score 0 · Answer 1 · answered Mar 09 '19 at 13:20

0

Use this

sort(x, key=lambda x: x[1])

answered Mar 09 '19 at 13:20

Pablo Martinez

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6

This does not provide an answer to the question. To critique or request clarification from an author, leave a comment below their post. - [From Review](/review/low-quality-posts/22416923) – Michał Ziober Mar 09 '19 at 14:08
@MichałZiober an answer being code-only [DOES NOT warrant deletion](https://meta.stackoverflow.com/q/256359/6296561). If you feel like it, downvote it, but deleting code-only is overkill in most cases (including this one). – Zoe Mar 09 '19 at 15:40

Geeocode · Answer 2 · 2019-03-09T13:40:25.707

According the original Python documentation:

Both list.sort() and sorted() have a key parameter to specify a function to be called on each list element prior to making comparisons.

Note that you can use both list.sort() or sorted():

Python lists have a built-in list.sort() method that modifies the list in-place. There is also a sorted() built-in function that builds a new sorted list from an iterable.

You can find some useful examples here.

# take second element for sort
def takeSecond(elem):
    return elem[1]

# your list
Nlist = [['naveen',31.5],['murali',44.1],['sai',23.1],['satya',23.1]]

# sort list with key
Nlist.sort(key=takeSecond)

# print list
print('Sorted list:', Nlist)

Out:

Sorted list: [['sai', 23.1], ['satya', 23.1], ['naveen', 31.5], ['murali', 44.1]]

How can I specify key argument in sort() function however complex the argument be?

2 Answers2