Tuples
A Tuple is a data structure very similar to a List, but with one major difference: it is immutable. This means once you create a tuple, you cannot change, add or remove its elements.
Key Characteristics
- Ordered: Tuples keep the order in which you first defined them.
- Immutable: You cannot modify them after creation (no appending or deleting).
- Allows Duplicates: You can have the same item multiple times.
- Heterogeneous: You can mix different types of data (strings, numbers, objects) in the same tuple.
Creating a Tuple
Tuples are created using parentheses
(), with items separated by commas.# Creating a tuple
my_tuple = ("apple", "banana", "cherry")
# Parentheses are actually optional, but recommended for readability
another_tuple = "red", "green", "blue"
The “Single Element” Rule
This is a common mistake for beginners! If you want a tuple with only one item, you must include a trailing comma. Without it, Python will just see it as a regular variable (like a string or integer).# WRONG: This is just a string
not_a_tuple = ("apple")
# RIGHT: This is a tuple
is_a_tuple = ("apple",)
Why Use a Tuple?
You use a Tuple when you want to ensure the data in your program stays the same.
- Safety: It prevents accidental changes to data that should remain constant (like the coordinates of a location or days of the week).
- Performance: Because they are “locked,” Tuples are slightly faster and use less memory than Lists.
List vs. Tuple: Quick Comparison
| Feature | List [] | Tuple () |
| Changeable? | Yes (Mutable) | No (Immutable) |
| Speed | Slower | Faster |
| Memory | Uses more memory | Uses less memory |
| Common Use | Items that change often | “Read-only” data |
Accessing Tuple Items
Just like Lists, Tuples use indexing. The first item starts at index
0.planets = ("Mercury", "Venus", "Earth", "Mars")
print(planets[0]) # Output: Mercury
print(planets[-1]) # Output: Mars (The last item)