delorean使用教程

henry14 發(fā)布于2019-07-31 11:39 / 2760人閱讀

摘要：可以使用進(jìn)行加減，得到一個對象也支持兩個時間比較提供多種方法獲取一個指定的時間，如明年或者下周三提供了一些方便的方法進(jìn)行如上操作。提供了很方便的方法按照微妙秒分鐘小時進(jìn)行過濾同樣，也支持按照年月份字符串處理另一個麻煩事是處理格式的字符串。

首先，約定三個概念。

navie datetime:沒有指定時區(qū)的datetime對象

localized datetime:指定時區(qū)的datetime對象

localizing:指定市區(qū)的的navie datetime

normalizing:datetime時區(qū)切換

一些例子

首先，導(dǎo)入Delorean

*>>> from delorean import Delorean

使用UTC格式的當(dāng)前時間創(chuàng)建一個datetime

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

簡單的時區(qū)切換

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

轉(zhuǎn)換成datetime看看

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

單純的輸入時間看看

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

也是用unix時間戳初始化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，就可以方便的切換到自己所需的時區(qū)
Delorean也可以使用指定的datetime對象進(jìn)行初始化，Delorean會自動處理時區(qū)和時間

*>>> 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的時間加減法。Delorean可以使用timedelta進(jìn)行加減，得到一個Delorean對象

*>>> 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也支持兩個時間比較

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

Delorean提供多種方法獲取一個指定的時間，如明年或者下周三
Delorean提供了一些方便的方法進(jìn)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、過去第二個周二午夜

*>>> 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=)

過濾

通常情況下我們不關(guān)心有多少微妙或者多少秒。例如，我們很難區(qū)別同一分鐘的兩個datetime對象。我們補(bǔ)習(xí)吧不關(guān)心的字段設(shè)置為0。
Delorean提供了很方便的方法按照微妙、秒、分鐘、小時進(jìn)行過濾

*>>> 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")

同樣，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")

字符串處理

另一個麻煩事是處理datetime格式的字符串。Delorean可以很方便的處理

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

歧義字段的處理

Delorean提供了兩個字段dayfirst=True and yearfirst=True用來處理相應(yīng)格式的字符串，如果dayfirst和yearfirst是True

YY-MM-DD

DD-MM-YY

MM-DD-YY

默認(rèn)情況下，對于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

時間步進(jìn)

*>>> 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
可以指定開始和結(jié)束的時間

*>>> 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")

只指定結(jié)束時間是不行的

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