# 将以数指定年、月、日的日期打印出来

months = [
    'January',
    'February',
    'March',
    'April',
    'May',
    'June',
    'July',
    'August',
    'September',
    'October',
    'November',
    'December'
    ]

# 一个列表，其中包含数1~31对应的英文结尾
endings = ['st','nd','rd'] + 17 * ['th']\
          + ['st','nd','rd'] + 7 * ['th'] + ['st']

year = input('Year: ')
month = input('Month(1-12): ')
day = input('Day(1-31): ')

month_number = int(month)
day_number = int(day)

# 别忘了将表示月和日的数减一，才能得到正确的索引
month_name = months[month_number-1]
ordinal = day + endings[day_number-1]

print(month_name + ' ' + ordinal + ', ' + year)

Year: 2020
Month(1-12): 2
Day(1-31): 22
February 22nd, 2020