You run the risk of an error without it.

I too was going to add .strip() to my code to take the spaces off the ends. However when I tested with just .join() it passed so I left it out

I was going for this but couldn't figure out how to use the strip in the same line.
End up adding a second line with: return words.strip('')
:-(

Best practices but... the test cases dont have trailing or leading whitespace

is it neccessary to put '[]' in the min() function?