Pyhton基础教程（第二版）chapter_2_1代码

#coding=utf_8
#注释中文必须加上第一行代码否则无法保存代码
#2016年11月9日17:52:00 by Nxtou
#根据给定的年月日以数字形式打印出日期
months = [
    'January',
    'February',
    'March',
    'April',
    'May',
    'June',
    'July',
    'August',
    'September',
    'October',
    'November',
    'December'
    ]
#以1-31的数字作为结尾的列表
endings = ['st','nd','rd']+17*['th']\
          +['st','nd','rd']+7*['th']\
          +['st']
year = raw_input('Year: ')
month = raw_input('Month (1-12): ')
day = raw_input('Day (1-31): ')
month_number = int(month)
day_number = int(day)

#记得要将月份和天数减1，以获得正确的索引
month_name = months[month_number-1]
ordinal = day + endings[day_number-1]
print month_name+' '+ordinal+'.'+year

运行结果：

>>> 
======================== RESTART: D:\Python27\2_1.py ========================
Year: 2016
Month (1-12): 11
Day (1-31): 9
November 9th.2016

代码解析：

endings = ['st','nd','rd']+17*['th']\
          +['st','nd','rd']+7*['th']\
          +['st']

起初看不懂这个17*[‘th’]，7*[‘th’]到底是什么意思，上网查了下资料，可以直接endings一下看看里面内容

>>> endings
['st', 'nd', 'rd', 'th', 'th', 'th', 'th', 'th', 'th', 'th', 'th', 'th', 'th', 'th', 'th', 'th', 'th', 'th', 'th', 'th', 'st', 'nd', 'rd', 'th', 'th', 'th', 'th', 'th', 'th', 'th', 'st']
>>> 

在根据代码看，这个17*[‘th’]，就是很明了了