class pandas.arrays.PeriodArray(values, freq=None, dtype=None, copy=False)[source]

Pandas ExtensionArray for storing Period data.

Users should use period_array() to create new instances.

values : Union[PeriodArray, Series[period], ndarray[int], PeriodIndex]

The data to store. These should be arrays that can be directly converted to ordinals without inference or copy (PeriodArray, ndarray[int64]), or a box around such an array (Series[period], PeriodIndex).

freq : str or DateOffset

The freq to use for the array. Mostly applicable when values is an ndarray of integers, when freq is required. When values is a PeriodArray (or box around), it’s checked that values.freq matches freq.

dtype : PeriodDtype, optional

A PeriodDtype instance from which to extract a freq. If both freq and dtype are specified, then the frequencies must match.

copy : bool, default False

Whether to copy the ordinals before storing.

See also

Create a new PeriodArray.
Immutable Index for period data.


There are two components to a PeriodArray

  • ordinals : integer ndarray
  • freq : pd.tseries.offsets.Offset

The values are physically stored as a 1-D ndarray of integers. These are called “ordinals” and represent some kind of offset from a base.

The freq indicates the span covered by each element of the array. All elements in the PeriodArray have the same freq.




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