what is the purpose of return_string = " " in the code below. Additionally what is happening in line 4 when " " is added to str(x)

def even_numbers(maximum):
    return_string = " "
    for x in range(2, maximum+1, 2):
        return_string += str(x) + " "
    return return_string.strip()

Hi i recently started learning how to code and i dont understand equating empty quotation marks and in some codes adding empty quotation marks to strings like in line 4

>Solution :

It’s not empty its a space.

lets say you add the following words

"hello" "freind"

Without the spaces it would become "hellofreind"

With the spaces it would be "hello freind"

Of course it also has a space at the begining so im assuming it gets added to another word