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Python Python Sequences Sequence Operations Concatenation and Multiplication

rosieg
rosieg
1,562 Points
Posted by rosieg
rosieg
1,562 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
229,732 Points
Steven Parker
Steven Parker
229,732 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
1,562 Points
rosieg
rosieg
1,562 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!