Using "and" in return

I'm taking Web Application Engineering course on Udacity. I noticed that the instructor use and operator in return statement in his validation method. And I didn't understand how it is possible to return 2 arguments. I think, it may be something like if statement. Could anyone explain what it actually is?

Here is the validation method:

USER_RE = re.compile(r"^[a-zA-Z0-9_-]{3,20}$")
def valid_username(username):
    return username and USER_RE.match(username)

Thanks in advance.