pandas.Series.first_valid_index#

Series.first_valid_index()[source]#

Return index for first non-NA value or None, if no non-NA value is found.

Returns:

type of index

Notes

If all elements are non-NA/null, returns None. Also returns None for empty Series/DataFrame.

Examples

For Series:

>>> s = pd.Series([None, 3, 4])
>>> s.first_valid_index()
1
>>> s.last_valid_index()
2

For DataFrame:

>>> df = pd.DataFrame({'A': [None, None, 2], 'B': [None, 3, 4]})
>>> df
     A      B
0  NaN    NaN
1  NaN    3.0
2  2.0    4.0
>>> df.first_valid_index()
1
>>> df.last_valid_index()
2