s += ns
        line = binascii.b2a_base64(s)
        output.write(line)


def decode(input, output):
    """Decode a file."""
    while True:
        line = input.readline()
        if not line:
            break
        s = binascii.a2b_base64(line)
        output.write(s)


def encodestring(s):
    """Encode a string into multiple lines of base-64 data."""
    pieces = []
    for i in range(0, len(s), MAXBINSIZE):
        chunk = s[i : i + MAXBINSIZE]
        pieces.append(binascii.b2a_base64(chunk))
    return "".join(pieces)


def decodestring(s):
    """Decode a string."""
    return binascii.a2b_base64(s)