pandas.Series.combine_first

Series.combine_first(self, other) [source]

Combine Series values, choosing the calling Series’s values first.

Parameters:	other : Series The value(s) to be combined with the Series.
Returns:	Series The result of combining the Series with the other object.

See also

Series.combine

Perform elementwise operation on two Series using a given function.

Notes

Result index will be the union of the two indexes.

Examples

>>> s1 = pd.Series([1, np.nan])
>>> s2 = pd.Series([3, 4])
>>> s1.combine_first(s2)
0    1.0
1    4.0
dtype: float64