def label_from_number(number):
    """
    Converts a number into an letter label (e.g. plate row label).

    :param number: The number you want to convert
    :type number: :class:`int`
    :return: The label corresponding to that number (:class:`string`).
    :Note: The function works with numbers, not with indices. If you are
           passing an index make sure to increment it by 1.
    """
    row_label_chars = []
    while number > 0:
        modulo = (number - 1) % 26
        row_label_chars.insert(0, chr(65 + modulo))
        number = (number - modulo) / 26
    return ''.join(row_label_chars)