df = X_train_raw.copy()

# Add a column to determine if the person can vote
df['can_vote'] = df['Age'].apply(lambda age: 1 if age >= 18 else 0)

# 892 passengers can vote; aka they are 18 or older
df['can_vote'].value_counts()

# Cabin letter: a cabin can be denoted as B123. The cabin letter will be B.
df.loc[:, 'cabin_letter'] = df['Cabin'].apply(
    lambda cabin: cabin[0] if cabin and type(cabin) is str else None,
)