pandas.DatetimeIndex.to_period — pandas 2.2.3 documentation (original) (raw)

DatetimeIndex.to_period(*args, **kwargs)[source]#

Cast to PeriodArray/PeriodIndex at a particular frequency.

Converts DatetimeArray/Index to PeriodArray/PeriodIndex.

Parameters:

freqstr or Period, optional

One of pandas’ period aliasesor an Period object. Will be inferred by default.

Returns:

PeriodArray/PeriodIndex

Raises:

ValueError

When converting a DatetimeArray/Index with non-regular values, so that a frequency cannot be inferred.

Examples

df = pd.DataFrame({"y": [1, 2, 3]}, ... index=pd.to_datetime(["2000-03-31 00:00:00", ... "2000-05-31 00:00:00", ... "2000-08-31 00:00:00"])) df.index.to_period("M") PeriodIndex(['2000-03', '2000-05', '2000-08'], dtype='period[M]')

Infer the daily frequency

idx = pd.date_range("2017-01-01", periods=2) idx.to_period() PeriodIndex(['2017-01-01', '2017-01-02'], dtype='period[D]')