pandas.Series.dt.is_year_start#

Series.dt.is_year_start[source]#

Indicate whether the date is the first day of a year.

Returns:

Series or DatetimeIndex

The same type as the original data with boolean values. Series willhave the same name and index. DatetimeIndex will have the samename.

See also

is_year_end

Similar property indicating the last day of the year.

Examples

This method is available on Series with datetime values underthe.dt accessor, and directly on DatetimeIndex.

>>>dates=pd.Series(pd.date_range("2017-12-30",periods=3))>>>dates0   2017-12-301   2017-12-312   2018-01-01dtype: datetime64[ns]

>>>dates.dt.is_year_start0    False1    False2    Truedtype: bool

>>>idx=pd.date_range("2017-12-30",periods=3)>>>idxDatetimeIndex(['2017-12-30', '2017-12-31', '2018-01-01'],              dtype='datetime64[ns]', freq='D')

>>>idx.is_year_startarray([False, False,  True])