map_filter_reduce_exercise.py

from functools import reduce


orders = [
    {
        'order_id': 98348,
        'title': 'A Moon Shaped Pool',
        'quantity': 4,
        'price': 40
    },
    {
        'order_id': 8439834,
        'title': 'In Rainbows',
        'quantity': 10,
        'price': 30
    },
    {
        'order_id': 98348934,
        'title': 'Kid A',
        'quantity': 8,
        'price': 45
    },
    {
        'order_id': 902384,
        'title': 'Ok Computer',
        'quantity': 20,
        'price': 60
    }
]

orders_computed = list(map(lambda item: (item['order_id'], item['quantity'] * item['price']), orders))

orders_filtered = list(filter(lambda item:  item[1] >= 300, orders_computed ))

total = reduce(lambda x, y: x + y[1], orders_filtered, 0)

total = reduce(lambda x, y: x + y[1], filter(lambda item:  item[1] >= 300, map(lambda item: (item['order_id'], item['quantity'] * item['price']), orders) ), 0)
print(total)