def string_with_fixed_length(s="", l=30):
    """
    Return a string with the contents of s plus white spaces until length l.
    :param s: input string
    :param l: total length of the string (will crop original string if longer than l)
    :return:
    """
    s_out = ""
    for i in range(0, l):
        if i < len(s):
            s_out += s[i]
        else:
            s_out += " "
    return s_out