Sometimes, we just have to manipulate a list of lists by appending a similar value to all the sublists. Using a loop for achieving this particular task can be an option but sometimes leads to sacrifice the readability of code. It is always wanted to have a oneliner to perform this particular task. Let’s discuss certain ways in which this can be done.
Method #1 : Using list comprehension
List comprehension can be used to perform this particular task using a similar looping construct but in just a single line. This increases code readability.
# Python3 code to demonstrate # appending single value # using list comprehension # initializing list of lists test_list = [[1, 3], [3, 4], [6, 5], [4, 5]] # printing original list print("The original list : " + str(test_list)) # declaring element to be inserted K = "GFG" # using list comprehension # appending single value res = [[i, j, K ] for i, j in test_list] # printing result print("The list after adding element : " + str(res)) |
The original list : [[1, 3], [3, 4], [6, 5], [4, 5]]
The list after adding element : [[1, 3, ‘GFG’], [3, 4, ‘GFG’], [6, 5, ‘GFG’], [4, 5, ‘GFG’]]
Method #2 : Using list comprehension + "+" operator
This method is quite similar to the above method, but the difference is that plus operator is used to add the new element to each sublist.
# Python3 code to demonstrate # appending single value # using list comprehension + "+" operator # initializing list of lists test_list = [[1, 3], [3, 4], [6, 5], [4, 5]] # printing original list print("The original list : " + str(test_list)) # declaring element to be inserted K = "GFG" # using list comprehension + "+" operator # appending single value res = [sub + [K] for sub in test_list] # printing result print("The list after adding element : " + str(res)) |
The original list : [[1, 3], [3, 4], [6, 5], [4, 5]]
The list after adding element : [[1, 3, ‘GFG’], [3, 4, ‘GFG’], [6, 5, ‘GFG’], [4, 5, ‘GFG’]]
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