Find Minimum by Attribute in Python

PythonPythonBeginner
Practice Now

This tutorial is from open-source community. Access the source code

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

%%%%{init: {'theme':'neutral'}}%%%% flowchart RL python(("`Python`")) -.-> python/BasicConceptsGroup(["`Basic Concepts`"]) python(("`Python`")) -.-> python/DataStructuresGroup(["`Data Structures`"]) python(("`Python`")) -.-> python/FunctionsGroup(["`Functions`"]) python/BasicConceptsGroup -.-> python/comments("`Comments`") python/DataStructuresGroup -.-> python/lists("`Lists`") python/DataStructuresGroup -.-> python/tuples("`Tuples`") python/DataStructuresGroup -.-> python/dictionaries("`Dictionaries`") python/FunctionsGroup -.-> python/function_definition("`Function Definition`") python/FunctionsGroup -.-> python/lambda_functions("`Lambda Functions`") python/FunctionsGroup -.-> python/build_in_functions("`Build-in Functions`") subgraph Lab Skills python/comments -.-> lab-13693{{"`Find Minimum by Attribute in Python`"}} python/lists -.-> lab-13693{{"`Find Minimum by Attribute in Python`"}} python/tuples -.-> lab-13693{{"`Find Minimum by Attribute in Python`"}} python/dictionaries -.-> lab-13693{{"`Find Minimum by Attribute in Python`"}} python/function_definition -.-> lab-13693{{"`Find Minimum by Attribute in Python`"}} python/lambda_functions -.-> lab-13693{{"`Find Minimum by Attribute in Python`"}} python/build_in_functions -.-> lab-13693{{"`Find Minimum by Attribute in Python`"}} end

Find the Minimum Value of a List Based on a Function

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.

def min_by(lst, fn):
  return min(map(fn, lst))
min_by([{ 'n': 4 }, { 'n': 2 }, { 'n': 8 }, { 'n': 6 }], lambda v : v['n']) ## 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.

Other Python Tutorials you may like