apply_example.py

import pandas as pd
from sklearn.datasets import load_iris

iris = load_iris()

df = pd.DataFrame(iris.data, columns=iris.feature_names)
# apply
cols = df.columns[0:4]
# divide each numeric column by 2
df[cols].apply(lambda x: x / 2).head()
# divide 1 column by 2
df.sepal_length_cm.apply(lambda x: x / 2).head()