041_Collections_OrderedDict.md

041 - Collections.OrderedDict()

Problem

collections.OrderedDict()

An OrderedDict is a dictionary that remembers the order of the keys that were inserted first. If a new entry overwrites an existing entry, the original insertion position is left unchanged.

Example

Code

from collections import OrderedDict

ordinary_dictionary = {}
ordinary_dictionary["a"] = 1
ordinary_dictionary["b"] = 2
ordinary_dictionary["c"] = 3
ordinary_dictionary["d"] = 4
ordinary_dictionary["e"] = 5
print(ordinary_dictionary)

ordered_dictionary = OrderedDict()
ordered_dictionary["a"] = 1
ordered_dictionary["b"] = 2
ordered_dictionary["c"] = 3
ordered_dictionary["d"] = 4
ordered_dictionary["e"] = 5
print(ordered_dictionary)

{'a': 1, 'c': 3, 'b': 2, 'e': 5, 'd': 4}
OrderedDict([('a', 1), ('b', 2), ('c', 3), ('d', 4), ('e', 5)])

Task

You are the manager of a supermarket.

You have a list of N items together with their prices that consumers bought on a particular day.

Your task is to print each item_name and net_price in order of its first occurrence.

_{item_name : Name of the item.
net_price : Quantity of the item sold multiplied by the price of each item.}

Input Format

The first line contains the number of items, N.

The next N lines contains the item's name and price, separated by a space.

Constraints

0 < N <= 100

Output Format

Print the item_name and net_price in order of its first occurrence.

Sample Input

9
BANANA FRIES 12
POTATO CHIPS 30
APPLE JUICE 10
CANDY 5
APPLE JUICE 10
CANDY 5
CANDY 5
CANDY 5
POTATO CHIPS 30

Sample Output

BANANA FRIES 12
POTATO CHIPS 60
APPLE JUICE 20
CANDY 20

Explanation

BANANA FRIES : Quantity bought : 1, Price 12
Net Price : 12
POTATO CHIPS : Quantity bought : 2, Price 30
Net Price : 60
APPLE JUICE : Quantity bought : 2, Price 10
Net Price : 20
CANDY : Quantity bought : 4, Price : 5
Net Price : 20

Solution

from collections import OrderedDict


sales = OrderedDict()

for i in range(int(input())):
    sale = input().split()
    item_name, price = " ".join(sale[:-1]), int(sale[-1])

    if item_name in sales:
        sales[item_name] += price
    else:
        sales[item_name] = price


print("\n".join([f"{k} {v}" for k,v in sales.items()]))