No, they are NOT strings, they are not any kind of strings. They are bytes:

    >>> b'asd'[0]
    97
    >>> b'asd'[1]
    115
    >>> b'asd'[2]
    100

They happen to contain an ASCII DECODABLE string in this case, but to get the text back, you NEED TO decode it first:

    >>> text = b'asd'.decode()
    >>> text[0]
    'a'
    >>> text[1]
    's'
    >>> text[2]
    'd'