Preferred way to remove whitespace from a string

I want to remove all spaces from a string.

" as fa sdf sdfsdf "

The result would be:

"asfasdfsdfsdf"

There are several ways I can think of to achieve this, and I'm wondering which one is the best.

1.

"".join(" as fa   sdf sdfsdf ".split())

2.

" as fa   sdf sdfsdf ".replace(" ", "")

And I assume that there are more.
Which one is preferred?