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Python Python Sequences Sequence Operations Concatenation and Multiplication

rosieg
rosieg
1,666 Points

Concatenating a tuple

My understanding is that tuples cannot be modified, ie if you add two tuples together the result has to be assigned to a new tuple. However, when I run the following code in the workspace:

tup1 = (1, 2, 3, 4, 5)
tup2 = (6, 7, 8, 9, 10)

tup1 = tup1 + tup2
print(tup1)

It works fine and returns (1, 2, 3, 4, 5, 6, 7, 9, 10). I expected it to fail as I am modifying tup1?

2 Answers

Steven Parker
Steven Parker
231,272 Points

What happens here is that the variable that originally contained the first tuple (tup1) is being reassigned with a newly created tuple built from both of the originals.

The original first tuple isn't modified, it is disposed.

If you want to see what happens when you attempt to modify a tuple, you could try something like this:

tup1[2] = 99
rosieg
rosieg
1,666 Points

Got you I think. The tuple isn't changed, the variable (tup1) is? And I have effectively just lost the original tup1 - something I will need to be careful of in the future!