Python时间，日期，时间戳之间转换

#1.将字符串的时间转换为时间戳方法:
a = "2013-10-10 23:40:00"
#将其转换为时间数组
import time

timeArray = time.strptime(a, "%Y-%m-%d %H:%M:%S")
# 转换为时间戳:
timeStamp = int(time.mktime(timeArray))
timeStamp == 1381419600

# 字符串格式更改如a = "2013-10-10 23:40:00", 想改为a = "2013/10/10 23:40:00"
# 方法:先转换为时间数组, 然后转换为其他格式
timeArray = time.strptime(a, "%Y-%m-%d %H:%M:%S")
otherStyleTime = time.strftime("%Y/%m/%d %H:%M:%S", timeArray)

# 3.时间戳转换为指定格式日期:
# 方法一:利用localtime()转换为时间数组, 然后格式化为需要的格式, 如
timeStamp = 1381419600
timeArray = time.localtime(timeStamp)
otherStyleTime = time.strftime("%Y-%m-%d %H:%M:%S", timeArray)
# otherStyletime == "2013-10-10 23:40:00"

# 方法二:
import datetime
timeStamp = 1381419600
dateArray = datetime.datetime.utcfromtimestamp(timeStamp)
otherStyleTime = dateArray.strftime("%Y-%m-%d %H:%M:%S")
# otherStyletime == "2013-10-10 23:40:00"

# 4.获取当前时间并转换为指定日期格式
# 方法一:
import time

# 获得当前时间时间戳
now = int(time.time())  #这是时间戳转换为其他日期格式, 如:"%Y-%m-%d %H:%M:%S"
timeArray = time.localtime(timeStamp)
otherStyleTime = time.strftime("%Y-%m-%d %H:%M:%S", timeArray)

# 方法二:
import datetime

# 获得当前时间
now = datetime.datetime.now()  #这是时间数组格式转换为指定的格式:
otherStyleTime = now.strftime("%Y-%m-%d %H:%M:%S")

# 5. 获得三天前的时间
# 方法:
import time
import datetime

# 先获得时间数组格式的日期
threeDayAgo = (datetime.datetime.now() - datetime.timedelta(days=3))
# 转换为时间戳:
timeStamp = int(time.mktime(threeDayAgo.timetuple()))
# 转换为其他字符串格式:
otherStyleTime = threeDayAgo.strftime("%Y-%m-%d %H:%M:%S")
# 注:timedelta()的参数有:days, hours, seconds, microseconds

# 6.给定时间戳, 计算该时间的几天前时间:
timeStamp = 1381419600
# 先转换为datetime
import datetime
import time

dateArray = datetime.datetime.utcfromtimestamp(timeStamp)
threeDayAgo = dateArray - datetime.timedelta(days=3)