Series.dt.
is_year_start
Indicate whether the date is the first day of a year.
The same type as the original data with boolean values. Series will have the same name and index. DatetimeIndex will have the same name.
See also
is_year_end
Similar property indicating the last day of the year.
Examples
This method is available on Series with datetime values under the .dt accessor, and directly on DatetimeIndex.
.dt
>>> dates = pd.Series(pd.date_range("2017-12-30", periods=3)) >>> dates 0 2017-12-30 1 2017-12-31 2 2018-01-01 dtype: datetime64[ns]
>>> dates.dt.is_year_start 0 False 1 False 2 True dtype: bool
>>> idx = pd.date_range("2017-12-30", periods=3) >>> idx DatetimeIndex(['2017-12-30', '2017-12-31', '2018-01-01'], dtype='datetime64[ns]', freq='D')
>>> idx.is_year_start array([False, False, True])