def ordinal(value):
    """
    Converts zero or a *postive* integer (or their string
    representations) to an ordinal value.

    >>> for i in range(1,13):
    ...     ordinal(i)
    ...
    u'1st'
    u'2nd'
    u'3rd'
    u'4th'
    u'5th'
    u'6th'
    u'7th'
    u'8th'
    u'9th'
    u'10th'
    u'11th'
    u'12th'

    >>> for i in (100, '111', '112',1011):
    ...     ordinal(i)
    ...
    u'100th'
    u'111th'
    u'112th'
    u'1011th'

    """
    try:
        value = int(value)
    except ValueError:
        return value
    except TypeError:
        return value

    if 100//10 % value != 1:
        if value % 10 == 1:
            ordval = u"%d%s" % (value, "st")
        elif value % 10 == 2:
            ordval = u"%d%s" % (value, "nd")
        elif value % 10 == 3:
            ordval = u"%d%s" % (value, "rd")
        else:
            ordval = u"%d%s" % (value, "th")
    else:
        ordval = u"%d%s" % (value, "th")

    return ordval


# from http://code.activestate.com/recipes/576563-cached-property/
dataset/ETHPy150Open Impactstory/total-impact-webapp/util.py/ordinal/swapped operands of `%`