Python.. Accessing the default sort function?

Question

Python Code:

b=['six', 'small', 'he', 'foxes', 'saw']
b.sort(key=len)
b

Output:

['he', 'six', 'saw', 'small', 'foxes']

In the above code, I sorted by length of elements and got the above output.

The output I want looks like this: ['he', 'saw', 'six', 'small', 'foxes']

So I want the first sort by length. Then for elements with the same length I want to sort alphabetically.

My question: Is there a way to do it without writing a custom function? Maybe something like this:

b.sort(key=[len,sorted]) # this doesn't work but I think it explains the idea.

Thanks!

Answer 1

We can use a compound sorting key, first sort by length, second lexicographically. We do this by creating a tuple, because tuples will naturally sort using the elements in the order they appear.

b = ['six', 'small', 'he', 'foxes', 'saw']
b.sort(key=lambda s: (len(s), s))

For the record, the above results in this sorted list::

['he', 'saw', 'six', 'foxes', 'small']

Which is the correct order as stipulated in the question (but the sample output in the question is wrong, so please be aware of it before downvoting!)