Python function: Insert None between list elements

Last update on April 01 2025 13:20:14 (UTC/GMT +8 hours)

9. Insert None Between Elements

Write a Python function that takes a list and returns a new list with None inserted between each element.

Sample Solution:

Code:

def insert_none(input_list):
    new_list = []
    for item in input_list:
        new_list.append(item)
        new_list.append(None)
    new_list.pop()  # Remove the last None added
    return new_list

def main():
    try:
        original_list = [2, 4, 6, 8, 10]
        new_list = insert_none(original_list)
        
        print("Original List:", original_list)
        print("New List with None:", new_list)
    except Exception as e:
        print("An error occurred:", e)

if __name__ == "__main__":
    main()

Output:

Original List: [2, 4, 6, 8, 10]
New List with None: [2, None, 4, None, 6, None, 8, None, 10]

In the exercise above, the "insert_none()" function iterates through the input list and appends each element to the new list, followed by a 'None'. After iterating through all elements, it removes the last 'None' added. Using a sample list and printing the original and new lists, the "main()" function demonstrates the function's usage.

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Python function that takes a list and returns a new list with None inserted between each consecutive element.
• Write a Python program to intersperse None values in a list using list comprehension, and then print the resulting list.
• Write a Python script to take an input list, insert None between each pair of elements, and then join the elements into a string representation.
• Write a Python function to modify a list by inserting a None value between every two adjacent elements, and then return the modified list.

Python Code Editor :

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