import datetime
a = str(datetime.date.today())
print(a)  # 格式为2015-07-17

time_str='Tue, 11 Nov 2014 06:37:20 +0000'
date = datetime.datetime.strptime(time_str, '%a, %d %b %Y %H:%M:%S %z')
print(date)  # 输出'2014-11-11 06:37:20+00:00'
print(date.timestamp()) # 输出时间戳'1415687840.0'

today = datetime.date.today()
datetime.datetime.combine(today, datetime.time.min)
# 得到datetime.datetime(2015, 7, 24, 0, 0)
datetime.datetime.combine(today, datetime.time.max)
# 得到datetime.datetime(2015, 7, 24, 23, 59, 59, 999999)

now = datetime.datetime.now()
date = now + datetime.timedelta(days = 1)

%d：日
%b：简写的月份，如Oct
%Y：年份
%H：小时
%m：月
%M：分钟
%S：秒
%z：与时区相关，在标准时间上加时间，例如'+00:00'