Remove non letter characters before and after characters in Python

To remove none letters characters from the beginning and end in python use regex from the re.py library. I needed it to remove spaces as well but not in between the words.

Here’s what I did:

import re

s = '( $My letters]'
s = re.sub('^[^a-zA-z]*|[^a-zA-Z]*$','',s)

print(s)

Output:

My letters