delorean使用教程

摘要：可以使用进行加减，得到一个对象也支持两个时间比较提供多种方法获取一个指定的时间，如明年或者下周三提供了一些方便的方法进行如上操作。提供了很方便的方法按照微妙秒分钟小时进行过滤同样，也支持按照年月份字符串处理另一个麻烦事是处理格式的字符串。

navie datetime:没有指定时区的datetime对象

localized datetime:指定时区的datetime对象

localizing:指定市区的的navie datetime

normalizing:datetime时区切换

首先，导入Delorean

*>>> from delorean import Delorean

使用UTC格式的当前时间创建一个datetime

*>>> d = Delorean()
*>>> d
Delorean(datetime=datetime.datetime(2013, 1, 12, 6, 10, 33, 110674),  timezone="UTC")

简单的时区切换

*>>> d = d.shift("US/Eastern")
*>>> d
Delorean(datetime=datetime.datetime(2013, 1, 12, 1, 10, 38, 102223), timezone="US/Eastern")

转换成datetime看看

*>>> d.datetime
datetime.datetime(2013, 1, 12, 01, 10, 38, 102223, tzinfo=)
*>>> d.date
datetime.date(2013, 1, 12)

单纯的输入时间看看

*>>> d.naive()
datetime.datetime(2013, 1, 12, 1, 10, 38, 102223)
*>>> d.epoch()
1357971038.102223

也是用unix时间戳初始化Delorean

*>>> from delorean import epoch
*>>> epoch(1357971038.102223).shift("US/Eastern")
Delorean(datetime=datetime.datetime(2013, 1, 12, 1, 10, 38, 102223), timezone="US/Eastern")

初始化后，就可以方便的切换到自己所需的时区
Delorean也可以使用指定的datetime对象进行初始化，Delorean会自动处理时区和时间

*>>> tz = timezone("US/Pacific")
*>>> dt = tz.localize(datetime.utcnow())
datetime.datetime(2013, 3, 16, 5, 28, 11, 536818, tzinfo=)
*>>> d = Delorean(datetime=dt)
*>>> d
Delorean(datetime=datetime.datetime(2013, 3, 16, 5, 28, 11, 536818), timezone="US/Pacific")
*>>> d = Delorean(datetime=dt, timezone="US/Eastern")
*>>> d
Delorean(datetime=datetime.datetime(2013, 3, 16, 5, 28, 11, 536818), timezone="US/Pacific")

Delorean支持timedelta的时间加减法。Delorean可以使用timedelta进行加减，得到一个Delorean对象

*>>> d = Delorean()
*>>> d
Delorean(datetime=datetime.datetime(2014, 6, 3, 19, 22, 59, 289779), timezone="UTC")
*>>> d += timedelta(hours=2)
*>>> d
Delorean(datetime=datetime.datetime(2014, 6, 3, 21, 22, 59, 289779), timezone="UTC")
*>>> d - timedelta(hours=2)
Delorean(datetime=datetime.datetime(2014, 6, 3, 19, 22, 59, 289779), timezone="UTC")
*>>> d2 = d + timedelta(hours=2)
*>>> d2 - d
datetime.timedelta(0, 7200)

Delorean也支持两个时间比较

*>>> d1 = Delorean(datetime(2015, 1, 1), timezone="US/Pacific")
*>>> d2 = Delorean(datetime(2015, 1, 1, 8), timezone="UTC")
*>>> d1 == d2
True

Delorean提供多种方法获取一个指定的时间，如明年或者下周三
Delorean提供了一些方便的方法进行如上操作。

*>>> d = Delorean()
*>>> d
Delorean(datetime=datetime.datetime(2013, 1, 20, 19, 41, 6, 207481), timezone="UTC")
*>>> d.next_tuesday()
Delorean(datetime=datetime.datetime(2013, 1, 22, 19, 41, 6, 207481), timezone="UTC")

上周二、过去第二个周二午夜

*>>> d.last_tuesday()
Delorean(datetime=datetime.datetime(2013, 1, 15, 19, 41, 6, 207481), timezone="UTC")
*>>> d.last_tuesday(2).midnight()
datetime.datetime(2013, 1, 8, 0, 0, tzinfo=)

通常情况下我们不关心有多少微妙或者多少秒。例如，我们很难区别同一分钟的两个datetime对象。我们补习吧不关心的字段设置为0。
Delorean提供了很方便的方法按照微妙、秒、分钟、小时进行过滤

*>>> d = Delorean()
*>>> d
Delorean(datetime=datetime.datetime(2013, 1, 21, 3, 34, 30, 418069), timezone="UTC")
*>>> d.truncate("second")
Delorean(datetime=datetime.datetime(2013, 1, 21, 3, 34, 30), timezone="UTC")
*>>> d.truncate("hour")
Delorean(datetime=datetime.datetime(2013, 1, 21, 3, 0), timezone="UTC")

同样，也支持按照年、月份

*>>> d = Delorean(datetime=datetime(2012, 5, 15, 03, 50, 00, 555555), timezone="US/Eastern")
*>>> d
Delorean(datetime=datetime.datetime(2012, 5, 15, 3, 50, 0, 555555), timezone="US/Eastern")
*>>> d.truncate("month")
Delorean(datetime=datetime.datetime(2012, 5, 1), timezone="US/Eastern")
*>>> d.truncate("year")

Delorean(datetime=datetime.datetime(2012, 1, 1), timezone="US/Eastern")

另一个麻烦事是处理datetime格式的字符串。Delorean可以很方便的处理

*>>> from delorean import parse
*>>> parse("2011/01/01 00:00:00 -0700")
Delorean(datetime=datetime.datetime(2011, 1, 1, 7), timezone="UTC")    

Delorean提供了两个字段dayfirst=True and yearfirst=True用来处理相应格式的字符串，如果dayfirst和yearfirst是True

YY-MM-DD

DD-MM-YY

MM-DD-YY

默认情况下，对于May 6th, 2013格式，Delorean返回‘2013-05-06

*>>> parse("2013-05-06")
Delorean(datetime=datetime.datetime(2013, 5, 6), timezone="UTC")

dayfirst和yearfirst的配置如下：

如果dayfirst是False，yearfirst是False

MM-DD-YY

DD-MM-YY

YY-MM-DD

如果dayfirst是True，yearfirst是False

DD-MM-YY

MM-DD-YY

YY-MM-DD

如果dayfirst是False，yearfirst是True

YY-MM-DD

MM-DD-YY

DD-MM-YY

*>>> import delorean
*>>> from delorean import stops
*>>> for stop in stops(freq=delorean.HOURLY, count=10):    print stop
...
Delorean(datetime=datetime.datetime(2013, 1, 21, 6, 25, 33), timezone="UTC")
Delorean(datetime=datetime.datetime(2013, 1, 21, 7, 25, 33), timezone="UTC")
Delorean(datetime=datetime.datetime(2013, 1, 21, 8, 25, 33), timezone="UTC")
Delorean(datetime=datetime.datetime(2013, 1, 21, 9, 25, 33), timezone="UTC")
Delorean(datetime=datetime.datetime(2013, 1, 21, 10, 25, 33), timezone="UTC")
Delorean(datetime=datetime.datetime(2013, 1, 21, 11, 25, 33), timezone="UTC")
Delorean(datetime=datetime.datetime(2013, 1, 21, 12, 25, 33), timezone="UTC")
Delorean(datetime=datetime.datetime(2013, 1, 21, 13, 25, 33), timezone="UTC")
Delorean(datetime=datetime.datetime(2013, 1, 21, 14, 25, 33), timezone="UTC")
Delorean(datetime=datetime.datetime(2013, 1, 21, 15, 25, 33), timezone="UTC")

注意：stops只接受naive datetime
可以指定开始和结束的时间

*>>> for stop in stops(freq=delorean.DAILY, count=10, timezone="US/Eastern", start=d1, stop=d2):    print stop
...
Delorean(datetime=datetime.datetime(2012, 5, 6), timezone="US/Eastern")
Delorean(datetime=datetime.datetime(2012, 5, 7), timezone="US/Eastern")
Delorean(datetime=datetime.datetime(2012, 5, 8), timezone="US/Eastern")
Delorean(datetime=datetime.datetime(2012, 5, 9), timezone="US/Eastern")
Delorean(datetime=datetime.datetime(2012, 5, 10), timezone="US/Eastern")
Delorean(datetime=datetime.datetime(2012, 5, 11), timezone="US/Eastern")
Delorean(datetime=datetime.datetime(2012, 5, 12), timezone="US/Eastern")
Delorean(datetime=datetime.datetime(2012, 5, 13), timezone="US/Eastern")
Delorean(datetime=datetime.datetime(2012, 5, 14), timezone="US/Eastern")
Delorean(datetime=datetime.datetime(2012, 5, 15), timezone="US/Eastern")

只指定结束时间是不行的

*>>> for stop in stops(freq=delorean.DAILY, timezone="US/Eastern", stop=d2):    print stop
...
Traceback (most recent call last):
    File "", line 1, in