Python Tuple

Python Tuple is an ordered sequence of immutable items.

Tuples are similar to lists, but once created the elements of a tuple can't be changed (tuples are immutable).

Create Python Tuples

A tuple is defined by listing the elements in round brackets ( ), separated by commas.

A tuple can have any number of elements and can be of different types (integer, float, list, string, etc.).

Let's look at the different types of tuples:

my_tuple = ()
print(my_tuple)  # ()

my_tuple = (1, 2, 3)
print(my_tuple)  # (1, 2, 3)

my_tuple = (1, "a string", 2.3)
print(my_tuple)  # (1, 'a string', 2.3)

my_tuple = ("a string", [8, 4, 6], (1, 2, 3))
print(my_tuple)  # ('a string', [8, 4, 6], (1, 2, 3))

A tuple can also be created without using parentheses. This operation is known as tuple packing.

my_tuple = 1, 2.3, "a string"
print(my_tuple)

a, b, c = my_tuple

print(a) # 1
print(b) # 2.3
print(c) # a string

Creating a tuple with a single element is a bit tricky, because it is not enough to have an element in parentheses: a final comma must be added to indicate that it is a tuple with a single element.

my_tuple = ("a string")
print(type(my_tuple))  # <class 'str'>

my_tuple = ("a string",)
print(type(my_tuple))  # <class 'tuple'>

my_tuple = "a string",
print(type(my_tuple))  # <class 'tuple'>

Access Tuple Elements

There are several ways to access items in a tuple.

with Index

The index operator [] can be used to access an item in a tuple.

• In Python, the tuple index starts from 0.
• The index must be an integer. Using values of any other type will result in a TypeError.
• Nested tuples are accessed using nested indexing.

my_tuple = ('t','u','t','o','r','i','a','l')

print(my_tuple[0])   # 't' 
print(my_tuple[5])   # 'i'

n_tuple = ("a string", [4, 5, 6], (1, 2, 3))

print(n_tuple[0][3]) # 't'
print(n_tuple[1][1]) # 5

with Negative Index

Python allows negative indexing for its sequences.

The index of -1 refers to the last item, -2 to the second last item and so on.

my_tuple = ('t', 'u', 't', 'o', 'r', 'i', 'a', 'l')

print(my_tuple[-1]) # l

print(my_tuple[-4]) # r

Slicing

A range of elements in a tuple can be accessed using the slicing operator :.

The possible cases (with examples) are shown in the table below:

Tuple Manipulation

Tuples are immutable, i.e, elements of a tuple can't be modified once assigned.

Change a Tuple

If the element of a tuple is a mutable data type, such as a list, its nested elements can be modified.

my_tuple = (4, 2, 3, [6, 5])


my_tuple[3][0] = 9    # Output: (4, 2, 3, [9, 5])
print(my_tuple)

Tuples can be reassigned to different values (reassignment).

my_tuple = ('t','u','t','o','r','i','a','l')
print(my_tuple) # ('t','u','t','o','r','i','a','l')
my_tuple = (1,2,3, [4,5] ) # reassign
print(my_tuple) # (1,2,3,4,5)

Concatenation an Repetition

The + operator is used to combine two tuples. This is called concatenation.

Using the * operator, elements of a tuple can be repeated a specific number of times to create a new tuple.

print((1, 2, 3) + (4, 5, 6)) # (1, 2, 3, 4, 5, 6)

print(("TutRef",) * 3) # ('TutRef', 'TutRef', 'TutRef')

Delete a Tuple

As mentioned above, it is not possible to modify the elements of a tuple.

However, it is possible to completely delete a tuple using the del statement

my_tuple = (0, 1, 2, 3, 4, 5)


del my_tuple

print(my_tuple)

Other Tuple Operations

Tuple Membership Test

The keyword in is used to check whether an item exists in a tuple.

my_tuple = ['t','u','t','o','r','i','a','l']
 
print('t' in my_tuple) # True
print('e' in my_tuple) # False
print('c' not in my_tuple) # True

Iterating Through a Tuple

Using a for loop, it is possible to iterate each element of a tuple.

for color in ('red','blue','yellow'):
    print("I'm wearing a", color, "t-shirt")

Output

I'm wearing a red t-shirt
I'm wearing a blue t-shirt
I'm wearing a yellow t-shirt

Summary of Python Tuple Methods

my_tuple = ('a', 'p', 'p', 'l', 'e',)

print(my_tuple.count('p'))  # Output: 2
print(my_tuple.index('l'))  # Output: 3