Tuples in Python

You just learned that lists can be changed after creation: items added, removed, updated. A tuple looks almost identical to a list, but comes with one key difference: once you create it, you can’t change it. That might sound limiting, but it’s actually the whole point.

What a tuple actually is

A tuple stores multiple values in order, just like a list, but you create it with round brackets instead of square ones.

colors = ("red", "green", "blue")
print(colors)

'''Output:
('red', 'green', 'blue')'''

Accessing items

Same indexing rules as a list, starting at 0, with negative indexes counting from the end.

colors = ("red", "green", "blue")
print(colors[0])    # red
print(colors[-1])   # blue

The main difference: tuples are immutable

Try to change an item in a tuple and Python stops you.

colors = ("red", "green", "blue")
colors[0] = "yellow" 

# Output
# TypeError: 'tuple' object does not support item assignment

This is by design. A tuple is meant for data that shouldn’t change once it’s set, coordinates, days of the week, a fixed set of settings.

Why use a tuple instead of a list

If your data isn’t supposed to change, a tuple protects it from being accidentally modified somewhere later in your code. It’s also slightly faster than a list, since Python doesn’t need to keep it flexible. In practice, that speed difference rarely matters for beginner projects, the real reason to reach for a tuple is when you want to guarantee the values stay fixed.

coordinates = (27.7172, 85.3240)

Nobody should be able to accidentally overwrite Kathmandu’s latitude halfway through a program. A tuple makes that mistake impossible instead of just unlikely.

A tuple with a single item

This one catches people off guard.

single = ("apple")
print(type(single))   # <class 'str'>, not a tuple!

Python treats ("apple") as just a string in brackets, not a tuple. To create a one-item tuple, you need a trailing comma.

single = ("apple",)
print(type(single))   # <class 'tuple'>

Easy to forget, and it’s a common source of confusing bugs.

Looping through a tuple

Works exactly like a list.

colors = ("red", "green", "blue")
for color in colors:
    print(color)

Checking length and membership

colors = ("red", "green", "blue")
print(len(colors))          # 3
print("green" in colors)    # True
print("purple" in colors)   # False

Converting between tuples and lists

If you do need to change a tuple’s contents, convert it to a list, make your changes, then convert it back.

colors = ("red", "green", "blue")
colors_list = list(colors)
colors_list.append("yellow")
colors = tuple(colors_list)
print(colors)   # ('red', 'green', 'blue', 'yellow')

Python Tuple Practice Questions

1. Create a tuple with the names of three countries and print the last one using negative indexing.
2. What is the output of the following code?
   Copy

   t = (1, 2, 3)
   t[1] = 10

3. Write code that checks whether “Nepal” exists inside a tuple of country names.
4. What type does x = ("hello") actually create? How would you fix it to make x a proper one-item tuple?
5. Write a program that converts a tuple of numbers into a list, adds one more number to it, then converts it back into a tuple.
6. Explain, in your own words, one real situation where you’d choose a tuple over a list.