Skip to content
Related Articles

Related Articles

Improve Article
Python | Find closest number to k in given list
  • Last Updated : 17 Oct, 2019

Given a list of numbers and a variable K, where K is also a number, write a Python program to find the number in a list which is closest to the given number K.

Examples:

Input : lst = [3.64, 5.2, 9.42, 9.35, 8.5, 8], K = 9.1
Output : 9.35

Input : lst = [9, 11, 5, 3, 25, 18], K = 6
Output : 5

 
Method #1 : Using min() method

In this approach, we use min method from Python and apply a key that finds the absolute difference of each element with K, and returns the element having minimum difference.




# Python3 program to find Closest number in a list
  
def closest(lst, K):
      
    return lst[min(range(len(lst)), key = lambda i: abs(lst[i]-K))]
      
# Driver code
lst = [3.64, 5.2, 9.42, 9.35, 8.5, 8]
K = 9.1
print(closest(lst, K))
Output:



9.35

 
Method #2 : Using numpy module

This approach applies the same method but using numpy module. First we convert the given list to an array. Find absolute difference with K of each element, and return the minimum from it.




# Python3 program to find Closest number in a list
import numpy as np
def closest(lst, K):
      
     lst = np.asarray(lst)
     idx = (np.abs(lst - K)).argmin()
     return lst[idx]
      
# Driver code
lst = [3.64, 5.2, 9.42, 9.35, 8.5, 8]
K = 9.1
print(closest(lst, K))
Output:
9.35

 Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.  

To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course. And to begin with your Machine Learning Journey, join the Machine Learning – Basic Level Course




My Personal Notes arrow_drop_up
Recommended Articles
Page :