How to Change List Items in Python: Update and Modify Values

Discover how to modify specific items in a Python list by changing their values using their index number. Learn the basics of updating list elements with practical examples and code snippets, including how to replace an item and print the updated list.

Python - Change List Items

Change Item Value

To change the value of a specific item in a list, refer to its index number:

thislist = ["orange", "grape", "melon"]
thislist[1] = "blueberry"
print(thislist)

['orange', 'blueberry', 'melon']

Change a Range of Item Values

To change multiple items within a specific range, define a list with the new values and refer to the range of index numbers where you want to insert the new values:

thislist = ["apple", "banana", "cherry", "orange", "kiwi", "mango"]
thislist[1:3] = ["blackcurrant", "watermelon"]
print(thislist)

['apple', 'blackcurrant', 'watermelon', 'orange', 'kiwi', 'mango']

If you insert more items than you replace, the new items will be inserted at the specified location, and the remaining items will shift accordingly:

thislist = ["apple", "banana", "cherry"]
thislist[1:2] = ["blackcurrant", "watermelon"]
print(thislist)

['apple', 'blackcurrant', 'watermelon', 'cherry']

Note: The length of the list will change if the number of items inserted does not match the number of items replaced.

If you insert fewer items than you replace, the new items will be inserted at the specified location, and the remaining items will shift accordingly:

thislist = ["apple", "banana", "cherry"]
thislist[1:3] = ["watermelon"]
print(thislist)

['apple', 'watermelon']

Insert Items

To insert a new item into a list without replacing any of the existing values, use the insert() method. This method inserts an item at the specified index:

thislist = ["apple", "banana", "cherry"]
thislist.insert(2, "watermelon")
print(thislist)

['apple', 'banana', 'watermelon', 'cherry']

Note: As a result of the above example, the list now contains 4 items.