Ordering a dictionary in Python

Question

I do not understand why this code does not return the list ordered:

A = {2:'a', 1: 'b', 3:'c'} 

R = list(a.keys()).sort()

In fact it does not return anything. I know I could do it in other ways like sorted(a.keys).

Thanks

Type `help(list(a.keys()).sort)` you'll see why. Do not call it, just use the `help` function on the method. — Countour-Integral, Dec 18 '20 at 00:22
`sort()` sorts the array in place and returns `None`. `sorted()` returns a new array. — Barmar, Dec 18 '20 at 00:22
`list.sort` returns `None`. It *does* sort the list, but you never maintain a reference to that list, so it is discarded. — juanpa.arrivillaga, Dec 18 '20 at 00:22
https://stackoverflow.com/questions/613183/how-do-i-sort-a-dictionary-by-value — Ken Lee, Dec 18 '20 at 00:26
All clear. Thank you. Do you think I should delete the question? — user5507798, Dec 18 '20 at 00:30

PIG208 · Accepted Answer · 2020-12-18T00:25:46.140

1

sort() does in-place changes to the list. What you can do is create a variable to store the keys and then sort it.

R = list(a.keys())
R.sort()

~~Use R = sorted(list(a.keys())) instead, as sort() serve as an in-place function~~

edited Dec 18 '20 at 00:25

answered Dec 18 '20 at 00:22

PIG208

1 Answers1