Drill 12: Compare — Cleaning data

import pandas as pd

df = pd.DataFrame({
    'course': ['CSS', 'CSS', 'SQL', None],
    'minutes': [18, 18, None, 9],
})

df = df.drop_duplicates()
df['minutes'] = df['minutes'].fillna(df['minutes'].median())
df = df.dropna(subset=['course'])
print(df)