python获取日期及格式化输出

# 获取日期：
importdatetime    #调用事件模块
today =datetime.date.today()    #获取今天日期
deltadays =datetime.timedelta(days=1)    #确定日期差额，如前天 days=2
yesterday =today -deltadays    # 获取差额日期，昨天
tomorrow =today +dletadays     # 获取差额日期，明天
# 格式化输出
ISOFORMAT='%Y%m%d' #设置输出格式
print today.strftime(ISOFORMAT)

更多格式化：

Python格式化日期时间的函数为datetime.datetime.strftime()；由字符串转为日期型的函数为：datetime.datetime.strptime()，两个函数都涉及日期时间的格式化字符串，列举如下：
%a     Abbreviated weekday name
%A     Full weekday name
%b     Abbreviated month name
%B     Full month name
%c     Date and time representation appropriate for locale
%d     Day of month as decimal number (01 - 31)
%H     Hour in 24-hour format (00 - 23)
%I     Hour in 12-hour format (01 - 12)
%j     Day of year as decimal number (001 - 366)
%m     Month as decimal number (01 - 12)
%M     Minute as decimal number (00 - 59)
%p     Current locale's A.M./P.M. indicator for 12-hour clock
%S     Second as decimal number (00 - 59)
%U     Week of year as decimal number, with Sunday as first day of week (00 - 51)
%w     Weekday as decimal number (0 - 6; Sunday is 0)
%W     Week of year as decimal number, with Monday as first day of week (00 - 51)
%x     Date representation for current locale
%X     Time representation for current locale
%y     Year without century, as decimal number (00 - 99)
%Y     Year with century, as decimal number
%z, %Z     Time-zone name or abbreviation; no characters if time zone is unknown
%%     Percent sign

另外参考：

格式化日期：

http://www.cnblogs.com/rollenholt/archive/2012/04/10/2441542.html

格式化时间：

http://hi.baidu.com/dooda/item/85ad5203f777add31ff04627