Pandas DatetimeIndex

Question

我试图在python中创建一个定制的datetime类，以支持时间序列模型。在回顾了一些现有的python库之后，我发现熊猫DatetimeIndex类提供了我正在寻找的很多功能，但是我仍然想为我的需要添加一些方法。我尝试用自定义的DatetimeIndex init构造函数对类进行子类化，然后调用超级init构造函数，但我似乎无法做到这一点。有人做过这个吗？如果能对如何做到这一点有一些见解，那就太好了。

这是我能想到的最简单的例子。下面是在一个名为time的模块中定义的类：

from pandas import DatetimeIndex

class DatetimeSub(DatetimeInex):

    def __init___(initTime):

        super().__init__(initTime)

当我用以下代码测试控制台中的类时：

import numpy as np

from time import DatetimeSub

testTime =  TimeEfo2(np.arange('1985-01-01 12:00','1985-02-01 12:00', dtype="datetime64[D]"))

我得到以下错误：

TypeError: object.init()只带一个参数(要初始化的实例)

我不明白这一点，因为您可以用一个DatetimeIndex数组实例化datetime64。此代码运行良好：

from pandas import DatetimeIndex

import numpy as np

dT = DatetimeIndex(np.arange('1985-01-01 12:00','1985-02-01 12:00', dtype="datetime64[D]"))

谢谢奎恩！这是可行的。如果我想创建自己的自定义构造函数，如：

from pandas import DatetimeIndex
import numpy as np

class DatetimeSub(DatetimeIndex):
    def __init__(self, bgnTime, endTime, unit = 'D'):
        # I am now constructing my numpy datetime64 array here:
        initTime = np.arange(bgnTime, endTime, dtype="datetime64[{}]".format(unit))
        # How do I call the super class to populate with the numpy array? This does not work:
        super().__init__(initTime)

谢谢!

Answer 1

构造函数的第一个参数总是self。因此，如果要将initTime作为第二个参数传入，则需要将其添加到构造函数中，如下所示：

from pandas import DatetimeIndex
import numpy as np

class DatetimeSub(DatetimeIndex):
    def __init__(self, initTime):
        super().__init__()

dt = DatetimeIndex(np.arange('1985-01-01 12:00','1985-02-01 12:00', dtype="datetime64[D]"))

ds = DatetimeSub(np.arange('1985-01-01 12:00','1985-02-01 12:00', dtype="datetime64[D]"))

print(dt)

print(ds)

输出：

DatetimeIndex(['1985-01-01', '1985-01-02', '1985-01-03', '1985-01-04',
               '1985-01-05', '1985-01-06', '1985-01-07', '1985-01-08',
               '1985-01-09', '1985-01-10', '1985-01-11', '1985-01-12',
               '1985-01-13', '1985-01-14', '1985-01-15', '1985-01-16',
               '1985-01-17', '1985-01-18', '1985-01-19', '1985-01-20',
               '1985-01-21', '1985-01-22', '1985-01-23', '1985-01-24',
               '1985-01-25', '1985-01-26', '1985-01-27', '1985-01-28',
               '1985-01-29', '1985-01-30', '1985-01-31'],
              dtype='datetime64[ns]', freq=None)
DatetimeSub(['1985-01-01', '1985-01-02', '1985-01-03', '1985-01-04',
             '1985-01-05', '1985-01-06', '1985-01-07', '1985-01-08',
             '1985-01-09', '1985-01-10', '1985-01-11', '1985-01-12',
             '1985-01-13', '1985-01-14', '1985-01-15', '1985-01-16',
             '1985-01-17', '1985-01-18', '1985-01-19', '1985-01-20',
             '1985-01-21', '1985-01-22', '1985-01-23', '1985-01-24',
             '1985-01-25', '1985-01-26', '1985-01-27', '1985-01-28',
             '1985-01-29', '1985-01-30', '1985-01-31'],
            dtype='datetime64[ns]', freq=None)