def S(self):
        "English ordinal suffix for the day of the month, 2 characters; i.e. 'st', 'nd', 'rd' or 'th'"
        if self.data.day in (11, 12, 13):  # Special case
            return 'th'
        last = self.data.day % 10
        if last == 1:
            return 'st'
        if last == 2:
            return 'nd'
        if last == 3:
            return 'rd'
        return 'th'
dataset/ETHPy150Open django/django/django/utils/dateformat.py/DateFormat.S/original