Lists and Tuples

Introduction to Tuples in Python

In this lesson, you will learn about tuples. You will understand their differences from lists, and explore typical use cases.

Let's create our first tuple:

my_tuple = ('Evan', 2, False)
 
print(my_tuple)

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Output

Looks almost like a list don't you think?

my_tuple = ('Evan', 2, False)
my_list = ['Evan', 2, False]
 
print(my_tuple, my_list)

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Output

So, besides the parentheses and square brackets, what's the difference?

Tuples are immutable, meaning their elements cannot be changed after creation. Lists, on the other hand, are mutable.

Let's see what happens if we try to update a tuple like we did with a list:

my_tuple = ('Evan', 2, False)
 
# attempt to change element at index 1
my_tuple[1] = 99
 
print(my_tuple)

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Output

Other than that, tauples are pretty similar to lists.

You can access tuple elements using indices and slicing:

my_tuple = (1, 2, 3, 4, 5)
 
# print first and last element
print(my_tuple[0], my_tuple[-1])
 
# print second and third element
print(my_tuple[1:3])

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Output

You can get the index of an element:

my_tuple = (1, 2, 3, 4, 5)
 
# print index of first occurrence of 3
print(my_tuple.index(3))

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Output

You can get the length of a tuple:

my_tuple = (1, 2, 3, 4, 5)
 
# print length of tuple
print(len(my_tuple))

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Output

There's more you can do with tuples, which will be covered in future chapters.

But, why should you use tuples?

First of all, the immutability of tuples can be advantageous.

If you have a collection of constant elements that never change, it's better to use a tuple to store them. This way, you cannot accidently change the values.

Using tuples for constant values also improves the readability of your code. When you encounter a tuple, you can be certain that its values remain unchanged.

Most importantly, tuples improve the performance of your code. Due to their immutability, they use less memory and accessing tuple elements is generally faster than accessing list elements.

That's why, whenever you have a collection of constant elements, store them in a tuple instead of a list.