pandas.Series.dt.to_period#

Series.dt.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 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年03月31日 00:00:00",
...  "2000年05月31日 00:00:00",
...  "2000年08月31日 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年01月01日", periods=2)
>>> idx.to_period()
PeriodIndex(['2017年01月01日', '2017年01月02日'],
 dtype='period[D]')