PythonVariables and Data TypesSequence Data typeTuple

Tuples in Python

A tuple in Python is a collection of ordered and immutable elements. Tuples are similar to lists but cannot be changed after creation. Because of their immutability, tuples are faster and used when the data should remain constant throughout the program.

Key Characteristics of Tuples

  • Ordered: The elements have a defined order.
  • Immutable: Once created, you cannot change, add, or remove elements.
  • Heterogeneous: Can store elements of different data types.
  • Indexable: Supports indexing and slicing like lists.
  • Hashable: Tuples can be used as dictionary keys (if all elements are hashable).

Creating Tuples

tuple_create.py
empty_tuple = ()
single_element = (10,)   # Must include a comma
mixed_tuple = (1, "hello", 3.5)

Explanation:

  • Parentheses () define a tuple.
  • A single-element tuple must have a trailing comma (e.g., (10,)), otherwise Python treats it as just a value in parentheses.

Example 1: Indexing and Accessing Elements

tuple_index.py
colors = ("red", "green", "blue")
print(colors[0])
print(colors[-1])
output.txt
red
blue

Explanation:

  • Indexing starts at 0.
  • Negative indices access elements from the end.

Example 2: Tuple Unpacking

tuple_unpacking.py
coordinates = (4, 5)
x, y = coordinates
print("X:", x, "Y:", y)
output.txt
X: 4 Y: 5

Explanation:

  • Tuple unpacking allows assigning elements of a tuple to multiple variables in one line.
  • The number of variables must match the number of elements in the tuple.

Example 3: Immutability of Tuples

tuple_immutable.py
t = (1, 2, 3)
t[0] = 10  # This will raise an error
output.txt
TypeError: 'tuple' object does not support item assignment

Explanation:

  • Tuples cannot be modified after creation.
  • This property makes them suitable for read-only or fixed data.

Example 4: Iterating Through Tuples

tuple_loop.py
languages = ("Python", "Java", "C++")
for lang in languages:
    print(lang)
output.txt
Python
Java
C++

Explanation:

  • Like lists, tuples support iteration using for loops.

Example 5: Tuple Methods – count() and index()

tuple_methods.py
nums = (1, 2, 2, 3, 4, 2)
print(nums.count(2))   # Count occurrences
print(nums.index(3))   # Index of value
output.txt
3
3

Explanation:

  • count(value) returns the number of times the value appears.
  • index(value) returns the first index where the value occurs.

Example 6: Nested Tuples

tuple_nested.py
info = ("John", (25, "Developer"))
print(info[1][0])  # Accessing inner tuple
output.txt
25

Explanation:

  • Tuples can contain other tuples (or other collections).
  • Indexing works recursively for nested structures.

When to Use Tuples Over Lists

CriteriaUse TupleUse List
MutabilityData should not changeData may change
PerformanceFaster (memory efficient)Slightly slower
Use as Dictionary KeyYes (if hashable)No
Semantic MeaningFixed group of related itemsDynamic collection

Summary

  • Tuples are ordered, immutable sequences.
  • They are defined with parentheses and support indexing, slicing, and unpacking.
  • They are useful when the data should not be modified, improving code safety and performance.
  • Tuples can be nested and used as keys in dictionaries.

In the next topic, we’ll explore Sets — another core collection type, useful for storing unique elements and performing set operations.

ListsSet Data type