Minimum Value by Attribute in Python

Introduction

In Python, you can use the min() function to find the minimum value of a list. However, what if you want to find the minimum value of a list based on a specific property or attribute of each element in the list? This is where the min_by() function comes in handy.

Skills Graph

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Find the Minimum Value of a List Based on a Function

Problem

Write a function called min_by(lst, fn) that takes a list lst and a function fn as arguments. The function should map each element in the list to a value using the provided function, and then return the minimum value.

Example

min_by([{ 'n': 4 }, { 'n': 2 }, { 'n': 8 }, { 'n': 6 }], lambda v : v['n']) ## 2

In the example above, the min_by() function is called with a list of dictionaries and a lambda function that extracts the value of the 'n' key from each dictionary. The function returns the minimum value of the list, which is 2.

Summary

In this challenge, you learned how to find the minimum value of a list based on a specific property or attribute of each element in the list using the min_by() function. This function maps each element in the list to a value using a provided function, and then returns the minimum value.