Pandas Apply Using Lambda Expression
In this example, we demonstrate the use of apply function using the lambda function.
import numpy as np
import pandas as pd
sample_df = pd.DataFrame( data=np.random.randint(1, 20, 18).reshape(6, 3),
columns=['x-val', 'y-val', 'z-val'])
sample_df
| x-val | y-val | z-val | |
|---|---|---|---|
| 0 | 9 | 7 | 2 |
| 1 | 19 | 4 | 18 |
| 2 | 7 | 13 | 13 |
| 3 | 10 | 6 | 2 |
| 4 | 15 | 3 | 17 |
| 5 | 3 | 10 | 7 |
Implementing the apply function with lambda expression
sample_df['new'] = sample_df['x-val'].apply(lambda x: x/100)
sample_df
| x-val | y-val | z-val | new | |
|---|---|---|---|---|
| 0 | 9 | 7 | 2 | 0.09 |
| 1 | 19 | 4 | 18 | 0.19 |
| 2 | 7 | 13 | 13 | 0.07 |
| 3 | 10 | 6 | 2 | 0.10 |
| 4 | 15 | 3 | 17 | 0.15 |
| 5 | 3 | 10 | 7 | 0.03 |