What is the purpose of key=None, how to use key ? What can we place in place of None ?

Question

I know that we can sort alphabetically/numerically in ascending or descending order by putting reverse = True or False
list.sort(key=None, reverse=False)

Answer 1

Here are a couple. You can use key= in both sorts, i.e. lst.sort(key=) and sorted(lst, key=)
https://code.sololearn.com/cwB76GNUFftP

The sort method sorts the list in place. The sorted function returns a sorted copy of the list.

lst1 = [1, 3, 2]
lst1.sort()
print(lst1) # output [1, 2, 3]

lst1 = [1, 3, 2]
print(sorted(lst1)) # output [1, 2, 3]

Answer 2

l = ["first", "second", "third", "fourth", "fifth"]
l.sort(key=len)
# sort by length
print(l)

Answer 3

At the bottom of the sort() doc there was a link that would have taken you to the "How To" area that would have described it further with examples. Here's that link.

https://docs.python.org/3/howto/sorting.html#sortinghowto

Answer 4

Here's a more detailed explanation
https://code.sololearn.com/cHAqka9YOVph

Answer 5

Read the section for list.sort() in the docs. It describes what the key is for and reverse is kinda obvious, but it is also described.

https://docs.python.org/3/library/stdtypes.html#list.sort

Answer 6

assuming you are talking of function signature:

if no values provided for 'key' and 'reverse' argument, default to 'None' (alphabetical sort) and 'False' (ascending order)

key is used to provide a sort function wich overide the default one...

Answer 7

ChaoticDawg there is no example provided in library/stdtypes, please provide me some example.

Answer 8

Привет здесь есть русские