Pandas | PeriodIndex constructor
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Pandas PeriodIndex(~) constructor creates a new PeriodIndex object, which represents a specific time span or a duration. PeriodIndex is most often used as the index of a DataFrame.
The difference between PeriodIndex and DatetimeIndex is as follows:
PeriodIndexrepresents a time span with a precise start and end time.DatetimeIndexrepresents a specific point in time.
Instead of calling this constructor directly, opt to use period_range(~) instead, which is more flexible and widely used.
Parameters
1. data | array-like | optional
An array-like containing the dates to construct the PeriodIndex.
2. copy | boolean | optional
If
True, then a new copy ofdatawill be returned - modifying this copied data will not mutate the originaldata, and vice versa.If
False, then the returned PeriodIndex will use the same memory block asdata. This means that modifying the return value will mutate the originaldata, and vice versa.
By default, copy=False.
3. freqlink | string or Period | optional
The frequency of the PeriodIndex. You can think of freq as the interval size of a time span. By default, the frequency is inferred from data.
4. yearlink | int or array or Series | optional
By default, year=None.
5. monthlink | int or array or Series | optional
By default, month=None.
6. quarter | int or array or Series | optional
By default, quarter=None.
7. daylink | int or array or Series | optional
By default, day=None.
8. hour | int or array or Series | optional
By default, hour=None.
9. minute | int or array or Series | optional
By default, minute=None.
10. second | int or array or Series | optional
By default, second=None.
11. tzlink | object | optional
The timezone to use when converting from datetime64 to PeriodIndex. By default, tz=None.
Return Value
A PeriodIndex object.
Examples
Basic usage
To create a PeriodIndex using a list of date-strings:
index_period = pd.PeriodIndex(["2020-12-25", "2020-12-26"], freq="D")index_period
PeriodIndex(['2020-12-25', '2020-12-26'], dtype='period[D]', freq='D')
Here, the freq="D" means that the interval size of each period is a day.
We can then use this PeriodIndex as the index of our DataFrame like so:
A2020-12-25 a2020-12-26 b
Specifying freq
To specify an interval size of the PeriodIndex, set freq like so:
index_period = pd.PeriodIndex(["2020-12-25", "2020-12-26"], freq="2D")index_period
PeriodIndex(['2020-12-25', '2020-12-26'], dtype='period[2D]', freq='2D')
Specifying individual time parameters
Instead of passing in data, you can create a PeriodIndex using individual time parameters like so:
idx = pd.PeriodIndex(year=[2000, 2002], month=[5,6], day=[10,11], freq="D")idx
PeriodIndex(['2000-05-10', '2002-06-11'], dtype='period[D]', freq='D')
Specifying tz
To make the PeriodIndex timezone-aware:
pd.PeriodIndex(["2020-12-25"], freq="D", tz="Asia/Tokyo")
PeriodIndex(['2020-12-25'], dtype='period[D]', freq='D')
