Pandas DataFrame ffill() Method
Example
Replace NULL values with the value from the previous row:
In this example we use a .csv file called data.csv
import pandas as pd
df = pd.read_csv('data.csv')
newdf = df.ffill()
Try it Yourself »
Definition and Usage
The ffill() method replaces the NULL values
with the value from the previous row (or previous column, if the
axis parameter is set to
'columns').
Syntax
dataframe.ffill(axis, inplace, limit, downcast)
Parameters
The axis, method,
axis, inplace,
limit, downcast parameters are
keyword arguments.
| Parameter | Value | Description |
|---|---|---|
| axis | 0 |
Optional, default 0. The axis to fill the NULL values along |
| inplace | True |
Optional, default False. If True: the replacing is done on the current DataFrame. If False: returns a copy where the replacing is done. |
| limit | NumberNone |
Optional, default None. Specifies the maximum number of NULL values to fill |
| downcast | DictionaryNone |
Optional, a dictionary of values to fill for specific data types |
Return Value
A DataFrame with the result, or None if the inplace parameter is set to True.
