Python Tuples

In Python, tuples are a built-in data type used to store multiple items in a single variable. Tuples are similar to lists but have some key differences, making them a useful choice in specific situations. This lesson will cover the characteristics of tuples, how to create them, and their usage in Python.

1. What is a Tuple?

A tuple is a collection that is both ordered and unchangeable (immutable). This means that once a tuple is created, you cannot change its contents (i.e., you cannot add, remove, or modify items).

Characteristics of Tuples:

• Ordered: The items in a tuple have a defined order, and that order will not change.
• Unchangeable: Tuples cannot be modified after creation.
• Allow Duplicates: Tuples can contain multiple items with the same value.

Example: Create a Tuple

1
2
thistuple = ("apple", "banana", "cherry")
print(thistuple)  # Output: ('apple', 'banana', 'cherry')

2. Tuple Items

Tuple items are indexed, with the first item having index [0], the second item having index [1], and so forth.

Example: Allowing Duplicate Values

1
2
thistuple = ("apple", "banana", "cherry", "apple", "cherry")
print(thistuple)  # Output: ('apple', 'banana', 'cherry', 'apple', 'cherry')

3. Tuple Length

To determine how many items are in a tuple, you can use the len() function.

Example: Print the Number of Items

1
2
thistuple = ("apple", "banana", "cherry")
print(len(thistuple))  # Output: 3

4. Creating a Tuple with One Item

To create a tuple with only one item, you must include a trailing comma after the item. Without the comma, Python will not recognize it as a tuple.

Example: One Item Tuple

1
2
3
4
5
6
thistuple = ("apple",)  # This is a tuple
print(type(thistuple))  # Output: <class 'tuple'>

# NOT a tuple
thistuple = ("apple")  # This is a string, not a tuple
print(type(thistuple))  # Output: <class 'str'>

5. Tuple Items - Data Types

Tuple items can be of any data type. You can have tuples containing strings, integers, booleans, and even other tuples.

Example: Different Data Types

1
2
3
4
5
6
tuple1 = ("apple", "banana", "cherry")  # Tuple of strings
tuple2 = (1, 5, 7, 9, 3)  # Tuple of integers
tuple3 = (True, False, False)  # Tuple of booleans

# A tuple with mixed data types
mixed_tuple = ("abc", 34, True, 40, "male")

6. What is the Data Type of a Tuple?

From Python's perspective, tuples are defined as objects with the data type 'tuple'.

Example: Check the Data Type

1
2
mytuple = ("apple", "banana", "cherry")
print(type(mytuple))  # Output: <class 'tuple'>

7. The tuple() Constructor

You can also create a tuple using the tuple() constructor. This method is useful when you want to create a tuple from an iterable.

Example: Using the tuple() Method

1
2
thistuple = tuple(("apple", "banana", "cherry"))  # Note the double round-brackets
print(thistuple)  # Output: ('apple', 'banana', 'cherry')