1-datetime
#1-获取当前日期和时间
from datetime import datetime
now = datetime.now() #当前时间
print(now) #2015-05-18 16:28:07.198690
#2-获取指定日期的时间
dt = datetime(2015,4,19,12,20)
print(dt) #2015-04-19 12:20:00
#3-datetime转换为timestamp
dt = datetime(2015,4,19,12,20)
print(dt.timestamp()) #1429417200.0 把datetime转换为timestamp
#某些编程语言（如Java和JavaScript）的timestamp使用整数表示毫秒数，
#这种情况下只需要把timestamp除以1000就得到Python的浮点表示方法。
#4-timestamp转换为datetime
t= 1429417200.0
print(datetime.fromtimestamp(t)) #2015-04-19 12:20:00
#5-str转换为datetime
cday = datetime.strptime('2015-6-1 18:19:59', '%Y-%m-%d %H:%M:%S')
print(cday) #2015-06-01 18:19:59
#6-datetime转换为str
now = datetime.now()
print(now.strftime('%a, %b %d %H:%M')) #Mon, May 05 16:28
#7-datetime加减
from datetime import datetime, timedelta
now = datetime.now()
now + timedelta(days=2, hours=12)
#8-本地时间转换为UTC时间
#1-获取当前日期和时间
from datetime import datet
