pandas.Series.combine_first

Series.combine_first(other)[source]

Update null elements with value in the same location in ‘other’.

Combine two Series objects by filling null values in one Series with non-null values from the other Series. Result index will be the union of the two indexes.

Parameters:

other:Series

The value(s) to be used for filling null values.

Returns:

Series

The result of combining the provided Series with the other object.

See also

Series.combine

Perform element-wise operation on two Series using a given function.

Examples

>>> s1 = pd.Series([1, np.nan])
>>> s2 = pd.Series([3, 4, 5])
>>> s1.combine_first(s2)
0    1.0
1    4.0
2    5.0
dtype: float64

Null values still persist if the location of that null value does not exist in other

>>> s1 = pd.Series({'falcon': np.nan, 'eagle': 160.0})
>>> s2 = pd.Series({'eagle': 200.0, 'duck': 30.0})
>>> s1.combine_first(s2)
duck       30.0
eagle     160.0
falcon      NaN
dtype: float64