Python Program to replace elements of a list based on the comparison with a number
Given a list, the task here is to write a Python program to replace its elements after comparing them with another number here described using K.
For the example depicted in this article, any number greater than K will be replaced with the value given in high and any number less than or equal to K will be replaced with the value given in low.
Input : test_list = [7, 4, 3, 2, 6, 8, 9, 1], low = 2, high = 9, K = 5
Output : [9, 2, 2, 2, 9, 9, 9, 2]
Explanation : Elements less than K substituted by 2, rest are by 9.
Input : test_list = [7, 4, 3, 2, 6, 8, 9, 1], low =2, high = 8, K = 5
Output : [8, 2, 2, 2, 8, 8, 8, 2]
Explanation : Elements less than K substituted by 2, rest are by 8.
Method 1 : Using loop
In this, we perform replacements using conditional statements and iteration is performed using loop.
Program:
Python3
# initializing list test_list = [ 7 , 4 , 3 , 2 , 6 , 8 , 9 , 1 ] # printing original list print ( "The original list is : " + str (test_list)) # initializing K K = 5 # initializing low and high Replacement Replacement low, high = 2 , 9 res = [] for ele in test_list: # conditional tests if ele > K: res.append(high) else : res.append(low) # printing result print ( "List after replacement ? : " + str (res)) |
Output:
The original list is : [7, 4, 3, 2, 6, 8, 9, 1]
List after replacement ? : [9, 2, 2, 2, 9, 9, 9, 2]
Method 2 : Using list comprehension
Similar to the method above, only difference is this is a one liner solution and a compact alternative using list comprehension.
Program:
Python3
# initializing list test_list = [ 7 , 4 , 3 , 2 , 6 , 8 , 9 , 1 ] # printing original list print ( "The original list is : " + str (test_list)) # initializing K K = 5 # initializing low and high Replacement Replacement low, high = 2 , 9 # list comprehension for shorthand solution res = [high if ele > K else low for ele in test_list] # printing result print ( "List after replacement ? : " + str (res)) |
Output:
The original list is : [7, 4, 3, 2, 6, 8, 9, 1]
List after replacement ? : [9, 2, 2, 2, 9, 9, 9, 2]