Python Pandas - 将 PeriodIndex 对象转换为时间戳并设置频率
要将 PeriodIndex 对象转换为时间戳,请使用 **PeriodIndex.to_timestamp()** 方法。使用 **freq** 参数设置频率。
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 numpy 数组,包含指示时间内规则周期的序号值。我们使用“freq”参数设置了频率 −
periodIndex = pd.PeriodIndex(['2021-09-25 07:30:35', '2019-10-30 04:15:45', '2020-07-15 02:55:15', '2022-06-25 09:40:55'], freq="Y")
显示 PeriodIndex 对象 −
print("PeriodIndex...\n", periodIndex)
将 PeriodIndex 转换为时间戳。我们使用“freq”参数设置了频率 −
print("\nPeriodIndex object to timestamp...\n", periodIndex.to_timestamp(freq='M'))
示例
代码如下 −
import pandas as pd # Create a PeriodIndex object # PeriodIndex is an immutable ndarray holding ordinal values indicating regular periods in time # We have set the frequency using the "freq" parameter periodIndex = pd.PeriodIndex(['2021-09-25 07:30:35', '2019-10-30 04:15:45', '2020-07-15 02:55:15', '2022-06-25 09:40:55'], freq="Y") # Display PeriodIndex object print("PeriodIndex...\n", periodIndex) # Display PeriodIndex frequency print("\nPeriodIndex frequency object...\n", periodIndex.freq) # Display PeriodIndex frequency as string print("\nPeriodIndex frequency object as a string...\n", periodIndex.freqstr) # Convert PeriodIndex to timestamp # We have set the frequency using the "freq" parameter print("\nPeriodIndex object to timestamp...\n", periodIndex.to_timestamp(freq='M'))
输出
将生成以下代码 −
PeriodIndex... PeriodIndex(['2021', '2019', '2020', '2022'], dtype='period[A-DEC]') PeriodIndex frequency object... <YearEnd: month=12> PeriodIndex frequency object as a string... A-DEC PeriodIndex object to timestamp... DatetimeIndex(['2021-01-31', '2019-01-31', '2020-01-31', '2022-01-31'], dtype='datetime64[ns]', freq=None)
广告