CODEWITHSUNDEEP
pythoncsv
Isac Moura
Isac Moura

Reputation: 6898

How to get the 10 highest values from a CSV file using Python without Pandas

I have a CSV file, and I turn this file into a dictionary using the DictReader from the CSV library.

My code is like that:

with open('file.csv', 'r') as file:
        reader = csv.DictReader(file)
        highest = sorted(reader, key=lambda x: (x['value']))
        print(highest)

But this is don't working and the list highest have all the data from the CSV and I only want the 10 highest values. But I don't know how to use limit the list to receive only the 10 highest values using dictionary.

I can't use Pandas

Upvotes: 1

Views: 1635

Answers (1)

blhsing
blhsing

Reputation: 106598

You can slice the list after sorting to get the 10 highest values:

highest = sorted(reader, key=lambda x: x['value'])[-10:]

You can also use the heapq.nlargest method to achieve the same in O(n log t) (where t is the number of items to return) time complexity instead of O(n log n):

import heapq
highest = heapq.nlargest(10, reader, key=lambda x: x['value'])

Upvotes: 4

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