Complex Lookp

complext_loop.py

# already sorted
for name, group in itertools.groupby(db_iter, key=lambda x: x[0]):
    total_sales = 0
    number_of_sales = 0
    earliest_sale = None
    latest_sale = None

    for _, amount, date in group:
        if amount is not None:
            total_sales += amount
            number_of_sales += 1
        if date is not None:
            if earliest_sale is None:
                earliest_sale = date
            latest_sale = date

    employee_stats = dict(
        total_sales=total_sales,
        number_of_sales=number_of_sales,
        earliest_sale=earliest_sale,
        latest_sale=latest_sale,
    )
    report(name, employee_stats)