def add_ordinal(num):
    """Returns a number with ordinal suffix, e.g., 1st, 2nd, 3rd.

    Args:
        num (int): a number

    Returns:
        (str): a number with the ordinal suffix

    Examples:
        >>> add_ordinal(11) == '11th'
        True
        >>> add_ordinal(132) == '132nd'
        True
    """
    switch = {1: "st", 2: "nd", 3: "rd"}
    end = "th" if (num % 100 in {11, 12, 13}) else switch.get(num % 10, "th")
    return "%i%s" % (num, end)