'Converts number to its ordinal English form.
This method converts 13 to 13th, 2 to 2nd ...'

def ordinalize(self, number):

    tail = 'th'
    if (((number % 100) == 11) or ((number % 100) == 12) or ((number % 100) == 13)):
        tail = 'th'
    elif ((number % 10) == 1):
        tail = 'st'
    elif ((number % 10) == 2):
        tail = 'nd'
    elif ((number % 10) == 3):
        tail = 'rd'
    return (str(number) + tail)
