pandas.DatetimeIndex.to_period#

DatetimeIndex.to_period(freq=None)[source]#

Cast to PeriodArray/PeriodIndex at a particular frequency.

Converts DatetimeArray/Index to PeriodArray/PeriodIndex.

Parameters:
freqstr or Period, optional

One of pandas’ period aliases or 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.

See also

PeriodIndex

Immutable ndarray holding ordinal values.

DatetimeIndex.to_pydatetime

Return DatetimeIndex as object.

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]')