python中的时间戳和日期的相互转化

#1--时间戳转化为日期
import datetime,time
timestamp = 163642240800
# 转换成localtime
time_local = time.localtime(timestamp / 1000)
# 转换成新的时间格式(精确到秒)
dt = time.strftime("%Y-%m-%d %H:%M:%S", time_local)
print(dt) #2021-11-09 09:46:48
d = datetime.datetime.fromtimestamp(timestamp / 1000)
# 精确到毫秒
str1 = d.strftime("%Y-%m-%d %H:%M:%S.%f")
print(str1) #2021-11-09 09:46:48.000000

#2-日期转化为时间戳
# 字符类型的时间
tss1 = '2021-06-03 21:19:03'
# 转为时间数组
timeArray = time.strptime(tss1, "%Y-%m-%d %H:%M:%S")
print(timeArray)
# timeArray可以调用tm_year等
print(timeArray.tm_year)
print(timeArray.tm_yday)
# 转为时间戳
timeStamp = int(time.mktime(timeArray))
print(timeStamp)


#3-python获取指定日期的前N天日期和后N天日期
#encoding:utf-8
from datetime import date, datetime, timedelta
day = date.today()
now = datetime.now()
delta = timedelta(days=5)
n_days_after = now + delta
n_days_forward = now - delta
print(("当前日期：{}").format(day))
print("向后推迟5天的日期：{}".format(n_days_after.strftime('%Y-%m-%d')))
print("向前推5天的日期：{}".format(n_days_forward.strftime('%Y-%m-%d')))

# 或者：
td = datetime.date.today()
#获取22天之后的日期
tm = (td + datetime.timedelta(days=22)).strftime('%Y-%m-%d')