Python Pandas - 创建一个 PeriodIndex 并获取一年中的哪一天

2026-06-03 1 花语

要创建PeriodIndex，请使用方法。使用PeriodIndex.dayofyear属性获取一年中的某一天。pandas.PeriodIndex()

首先，导入所需的库-

import pandas as pd

创建一个PeriodIndex对象。PeriodIndex是一个不可变的ndarray，其中包含指示定期时间段的序数值。我们使用“freq”参数设置了频率-

periodIndex = pd.PeriodIndex([2018-07-25, 2019-10-30, 2020-11-20, 2021-09-15, 2022-03-12, 2023-06-18], freq="D")

显示PeriodIndex对象-

print("PeriodIndex...\n", periodIndex)

从PeriodIndex对象显示一年中的第几天-

print("\nDays of the year from the PeriodIndex...\n", periodIndex.dayofyear)

示例

以下是代码-

import pandas as pd #CreateaPeriodIndexobject #PeriodIndexisanimmutablendarrayholdingordinalvaluesindicatingregularperiodsintime # We have set the frequency using the "freq" parameter periodIndex = pd.PeriodIndex([2018-07-25, 2019-10-30, 2020-11-20, 2021-09-15, 2022-03-12, 2023-06-18], freq="D") #DisplayPeriodIndexobject print("PeriodIndex...\n", periodIndex) #DisplayPeriodIndexfrequency print("\nPeriodIndex frequency...\n", periodIndex.freq) #DisplaydayfromthePeriodIndexobject print("\nThe number of days from the PeriodIndex...\n", periodIndex.day) #DisplaydayoftheyearfromthePeriodIndexobject print("\nDays of the year from the PeriodIndex...\n", periodIndex.dayofyear)输出结果

这将产生以下代码-

PeriodIndex... PeriodIndex([2018-07-25, 2019-10-30, 2020-11-20, 2021-09-15, 2022-03-12, 2023-06-18], dtype=period[D]) PeriodIndex frequency... <Day> The number of days from the PeriodIndex... Int64Index([25, 30, 20, 15, 12, 18], dtype=int64) Days of the year from the PeriodIndex... Int64Index([206, 303, 325, 258, 71, 169], dtype=int64)