Python Practice › Pandas Programs › Program 89
Fill from the previous row
Write a pandas program to replace NaN with the value from the previous row.
Output
name age 0 Alex 30.0 1 Alex 30.0 2 Peter 29.0 3 Klaus 22.0
Approach
ffill().
Solution
import numpy as npimport pandas as pddf = pd.DataFrame({"name": ["Alex", np.nan, "Peter", "Klaus"], "age": [30, np.nan, 29, 22]})print(df.ffill())Output
name age 0 Alex 30.0 1 Alex 30.0 2 Peter 29.0 3 Klaus 22.0
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