Python: Get the n expensive and cheap price items from a given dataset using Heap queue algorithm

Python heap queue algorithm: Exercise-10 with Solution

Write a Python program to get the n expensive and cheap price items from a given dataset using Heap queue algorithm.

Sample Solution:

Python Code:

import heapq
from pprint import pprint
items = [
    {'name': 'Item-1', 'price': 101.1},
    {'name': 'Item-2', 'price': 555.22},
    {'name': 'Item-3', 'price': 45.09},
    {'name': 'Item-4', 'price': 22.75},
    {'name': 'Item-5', 'price': 16.30},
    {'name': 'Item-6', 'price': 110.65}
]

cheap = heapq.nsmallest(3, items, key=lambda s: s['price'])
expensive = heapq.nlargest(3, items, key=lambda s: s['price'])
print("Original datasets:")
pprint(items)
print("\nFirst 3 expensive items:")
pprint(expensive)
print("\nFirst 3 cheap items:")
pprint(cheap)

Sample Output:

Original datasets:
[{'name': 'Item-1', 'price': 101.1},
 {'name': 'Item-2', 'price': 555.22},
 {'name': 'Item-3', 'price': 45.09},
 {'name': 'Item-4', 'price': 22.75},
 {'name': 'Item-5', 'price': 16.3},
 {'name': 'Item-6', 'price': 110.65}]

First 3 expensive items:
[{'name': 'Item-2', 'price': 555.22},
 {'name': 'Item-6', 'price': 110.65},
 {'name': 'Item-1', 'price': 101.1}]

First 3 cheap items:
[{'name': 'Item-5', 'price': 16.3},
 {'name': 'Item-4', 'price': 22.75},
 {'name': 'Item-3', 'price': 45.09}]

Flowchart:

Visualize Python code execution:

The following tool visualize what the computer is doing step-by-step as it executes the said program:

Python Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous: Write a Python program to find the top k integers that occur the most frequently from a given lists of sorted and distinct integers using Heap queue algorithm.
Next: Write a Python program to merge multiple sorted inputs into a single sorted iterator (over the sorted values) using Heap queue algorithm.