 # Python | List of custom cycles

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Method # 1: Using a Loop
Loops can accomplish this task. In this, we simply iterate over the list to change the Kth element to the predefined N in the code.

 ` # Python3 code to demonstrate how it works ` ` # Adding N to the Kth tuple element ` ` # Using a loop ` ` `  ` # Initializing list ` ` test_list ` ` = ` ` [(` ` 4 ` `, ` ` 5 ` `, ` ` 6 ` `), ( ` ` 7 ` `, ` ` 4 ` `, ` ` 2 ` `), (` ` 9 ` , ` 10 ` `, ` ` 11 ` `)] `   ` # print the original list ` ` print ` ` (` ` "The original list is : "` ` + ` ` str ` ` (test_list)) `   ` # Initialization N ` ` N ` ` = ` ` 3 `  ` `  ` # Initialize K ` ` K ` ` = ` ` 1 `   ` # Add N to element of Kth tuple ` ` # Using a loop ` ` res ` ` = [] ```` for i in range ( 0 , len (test_list)): res.append ((test_list [i] [ 0 ], test_list [i] [K] + N, test_list [i] [ 2 ]))   # print result print ( "The tuple after adding N to Kth element:" + str (res)) ```

Output:

` The original list is: [(4, 5, 6) , (7, 4, 2), (9, 10, 11)] The tuple after adding N to Kth element: [(4, 8, 6), (7, 7, 2), (9, 13, 11) ] `

Method # 2: Using a List Comprehension
This method takes the same approach as the previous method, just shortening lines of code using list comprehension functionality to keep the code compact.

 ` # Python3 code to demonstrate how it works ` ` # Adding N to the Kth tuple element ` ` # Using the comprehension list `   ` # Initializing list ```` test_list = [( 4 , 5 , 6 ), ( 7 , 4 , 2 ), ( 9 , 10 , 11 )]    # print original list print ( "The original list is:" + str (test_list))    # Initializing N N = 3     # Initializing K K = 1    # Adding N to the Kth tuple element # Using comprehension list res = [(a, b + N, c) for a, b, c in test_list]   # print result print ( "The tuple after adding N to Kth element:" + str (res)) ```

Output:

` The original list is: [(4, 5, 6), (7, 4, 2), (9, 10, 11)] The tuple after adding N to Kth element: [(4, 8, 6), (7, 7, 2), (9, 13, 11)] `
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