pandas.DataFrame.bfill#

DataFrame.bfill(*, axis=None, inplace=False, limit=None, downcast=None)[source]#

Synonym for DataFrame.fillna() with method='bfill'.

Returns:

Series/DataFrame or None: Object with missing values filled or None if inplace=True.

Examples

For Series:

>>> s = pd.Series([1, None, None, 2])
>>> s.bfill()
0    1.0
1    2.0
2    2.0
3    2.0
dtype: float64
>>> s.bfill(downcast='infer')
0    1
1    2
2    2
3    2
dtype: int64
>>> s.bfill(limit=1)
0    1.0
1    NaN
2    2.0
3    2.0
dtype: float64

With DataFrame:

>>> df = pd.DataFrame({'A': [1, None, None, 4], 'B': [None, 5, None, 7]})
>>> df
      A     B
0   1.0   NaN
1   NaN   5.0
2   NaN   NaN
3   4.0   7.0
>>> df.bfill()
      A     B
0   1.0   5.0
1   4.0   5.0
2   4.0   7.0
3   4.0   7.0
>>> df.bfill(downcast='infer', limit=1)
      A    B
0   1.0    5
1   NaN    5
2   4.0    7
3   4.0    7