# pandas.DataFrame.first¶

DataFrame.first(self: ~ FrameOrSeries, offset) → ~FrameOrSeries[source]

Method to subset initial periods of time series data based on a date offset.

Parameters
offsetstr, DateOffset, dateutil.relativedelta
Returns
subsetsame type as caller
Raises
TypeError

If the index is not a DatetimeIndex

last

Select final periods of time series based on a date offset.

at_time

Select values at a particular time of the day.

between_time

Select values between particular times of the day.

Examples

>>> i = pd.date_range('2018-04-09', periods=4, freq='2D')
>>> ts = pd.DataFrame({'A': [1,2,3,4]}, index=i)
>>> ts
A
2018-04-09  1
2018-04-11  2
2018-04-13  3
2018-04-15  4


Get the rows for the first 3 days:

>>> ts.first('3D')
A
2018-04-09  1
2018-04-11  2


Notice the data for 3 first calender days were returned, not the first 3 days observed in the dataset, and therefore data for 2018-04-13 was not returned.