datetime, timedelta
datetime为时间类，timedelta为时间差类
from datetime import datetime,timedelta
today = datetime.today()
week = timedelta(days=7)
lastWeek = today - week
print lastWeek
d = datetime(1949,10,1)
print (today-d).days
caldendar 找出当月的日期范围
from datetime import datetime,timedelta, date
import calendar
def get_month_range(start_date=None):
if start_date is None:
start_date = date.today().replace(day=1)
_, days_in_month = calendar.monthrange(start_date.year, start_date.month)
end_date = start_date + timedelta(days=days_in_month)
return (start_date, end_date)
print get_month_range() #(datetime.date(2016, 9, 1), datetime.date(2016, 10, 1))
字符串转换为日期
from datetime import datetime
text = "2012-09-20"
y = datetime.strptime(text, '%Y-%m-%d')
print y
日期转换为字符串
from datetime import datetime
t = datetime(2012,9,23,21,37,4)
print datetime.strftime(t,'%A %B %d, %Y')
