Python Program to replace list elements within a range with a given number
Given a range, the task here is to write a python program that can update the list elements falling under a given index range with a specified number.
Input : test_list = [4, 6, 8, 1, 2, 9, 0, 10, 12, 3, 9, 1], i, j = 4, 8, K = 9
Output : [4, 6, 8, 1, 9, 9, 9, 9, 12, 3, 9, 1]
Explanation : List is updated with 9 from 4th to 8th index.
Input : test_list = [4, 6, 8, 1, 2, 9, 0, 10, 12, 3, 9, 1], i, j = 4, 8, K = 8
Output : [4, 6, 8, 1, 8, 8, 8, 8, 12, 3, 9, 1]
Explanation : List is updated with 8 from 4th to 8th index.
Method 1 : Using slicing and * operator
In this, we perform task of getting elements of range using slicing and * operator is used to perform update and provide required elements to fill updates.
Program:
Python3
# initializing listtest_list = [4, 6, 8, 1, 2, 9, 0, 10, 12, 3, 9, 1] # printing original listprint("The original list is : " + str(test_list)) # initializing i, ji, j = 4, 8 # initializing KK = 9 # getting range using slicing and# required elements using * operatortest_list[i:j] = [K] * (j - i) # printing resultprint("Range Updated list : " + str(test_list)) |
Output:
The original list is : [4, 6, 8, 1, 2, 9, 0, 10, 12, 3, 9, 1]
Range Updated list : [4, 6, 8, 1, 2, 9, 0, 10, 12, 3, 9, 1, 9]
Method 2 : Using repeat() and list slicing
The similar task can also be performed using repeat(), which uses unbuilt constructs to get required elements.
Program:
Python3
from itertools import repeat # initializing listtest_list = [4, 6, 8, 1, 2, 9, 0, 10, 12, 3, 9, 1] # printing original listprint("The original list is : " + str(test_list)) # initializing i, ji, j = 4, 8 # initializing KK = 9 # getting range using slicing and# required elements using repeat()test_list[i:j] = repeat(K, (j - i)) # printing resultprint("Range Updated list : " + str(test_list)) |
Output:
The original list is : [4, 6, 8, 1, 2, 9, 0, 10, 12, 3, 9, 1]
Range Updated list : [4, 6, 8, 1, 2, 9, 0, 10, 12, 3, 9, 1, 9]
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