Python - Update Tuples

In Python, tuple is an immutable data type. An immutable object cannot be modified once it is created in the memory.

Example

If we try to assign a new value to a tuple item with slice operator, Python raises TypeError. See the following example −

tup1 = ("a", "b", "c", "d")
tup1[2] = 'Z'
print ("tup1: ", tup1)

It will produce the following output −

Traceback (most recent call last):
 File "C:\Users\mlath\examples\main.py", line 2, in <module>
  tup1[2] = 'Z'
  ~~~~^^^
TypeError: 'tuple' object does not support item assignment

Hence, it is not possible to update a tuple. Therefore, the tuple class doesn't provide methods for adding, inserting, deleting, sorting items from a tuple object, as the list class.

Change Tuple Values in Python

You can use a work-around to update a tuple. Using the list() function, convert the tuple to a list, perform the desired append/insert/remove operations and then parse the list back to tuple object.

Example

Here, we convert the tuple to a list, update an existing item, append a new item and sort the list. The list is converted back to tuple.

tup1 = ("a", "b", "c", "d")
print ("Tuple before update", tup1, "id(): ", id(tup1))

list1 = list(tup1)
list1[2]='F'
list1.append('Z')
list1.sort()
print ("updated list", list1)

tup1 = tuple(list1)
print ("Tuple after update", tup1, "id(): ", id(tup1))

It will produce the following output −

Tuple before update ('a', 'b', 'c', 'd') id(): 2295023084192
updated list ['F', 'Z', 'a', 'b', 'd']
Tuple after update ('F', 'Z', 'a', 'b', 'd') id(): 2295021518128

However, note that the id() of tup1 before update and after update are different. It means that a new tuple object is created and the original tuple object is not modified in-place.