python 日期 datetime和timedelta 使用方法

from datetime import datetime
from datetime import timedelta

# 1) 获取当前日期和时间
today = datetime.today()    # 返回当前时间时分秒都为0
print("当前时间")
print(today)
today1 = datetime.now()  # 返回当前日期和时间
now.hour # 时
now.minute # 分
now.isoweekday（）# 返回的1-7代表周一--周日；
now.weekday（）# 返回的0-6代表周一--到周日
# 而标准格式种%w 1-6表示周一--周六，0代表周日
print( today1 )
today2 = datetime.utcnow()  # 返回当前东八区时间就是比当时时间少8个小时
print(today2)


# 2) 获取指定日期和时间,加减计算
time= datetime(2019, 5, 12, 12, 13, 14)
d= time + timedelta(weeks=0, days=0, hours=0, minutes=0,  seconds=0, milliseconds=0, microseconds=0, )		
#依次为 "周" "天", "时","分","秒","毫秒","微秒"
print(time)
print(d)

time1= "2019-5-12 12:13:14"		# 字符串 日期
d1 = datetime.strptime(str(time1),'%Y-%m-%d %H:%M:%S')
plus= d1 + timedelta(days=1)		# 加
minus = d1 - timedelta(days=1)		# 减
print(time1)
print(d1)
print(plus)
print(minus )

time2= 20190512121314
d2 = datetime.strptime(str(time2),'%Y%m%d%H%M%S')
delta = d2  + timedelta(days=1)
print(time2)
print(d2 )
print(delta)

# 3) 日期datetime-timestamp 时间戳相互转
now_stamp = time.timestamp()
print('指定时间对应时间戳 :', now_stamp)

print('对应本地时间 :', datetime.fromtimestamp(now_stamp ))
print('UTC标准时间 :', datetime.utcfromtimestamp(now_stamp ))
print('本周的第几天:', datetime.fromtimestamp(now_stamp ).weekday())


# 4) datetime 时间 转换为str字符串
now = datetime.now()
print('当前时间 :', now)
print(now.strftime('%Y%m%d%H%M%S'))