การลบข้อมูลซ้ำ

# Drop duplicate store/type combinations
store_types = ____
print(store_types.head())

# Drop duplicate store/department combinations
store_depts = ____
print(store_depts.head())

# Subset the rows where is_holiday is True and drop duplicate dates
holiday_dates = sales[sales[____]].drop_duplicates(____)

# Print date col of holiday_dates
print(____)