01
02
03
04
05
06
07
08
09
10
11
12
import pandas as pd
import numpy as np
df = pd.DataFrame({'Name': ['David', 'Glenn', 'Steve'], 'Subjects': [
['English', 'Math'], ['Math'], ['Science', 'English']]})
lens = list(map(len, df['Subjects'].values))
res = pd.DataFrame({'Name': np.repeat(
df['Name'], lens), 'Subject': np.concatenate(df['Subjects'].values)})
print(res)