Python Tutorial - Data Type-Tuple

1. Advantages of Tuple Over List
2. Create a Tuple
3. Access Tuple Elements
4. Python Tuple Methods
5. Tuple Built-In Functions:
6. Tuple Membership Check
7. Iterate Through a Tuple

In this section, we will introduce how to create and use tuples.

A tuple is similar to a list with the difference that the tuple is immutable but the list is mutable.

Advantages of Tuple Over List

1. Tuples are mostly used when the elements have different data types whereas, lists are used when the elements are of the same data type.
2. Traversing through tuples is faster as you cannot update a tuple.
3. You can use the immutable elements of the tuple as a key in the dictionary. This cannot be done with a list.
4. Tuples guarantee the protection of the data as they are immutable.

Create a Tuple

You can define a Python tuple using parenthesis () and separate elements with commas ,. A tuple can have elements of any data type.

>>> x = (3, 'pink', 3+8j)
>>> print('x[0] =', x[0])
x[0] = 3
>>> print('x[0:2] =', x[0:2])
x[0:2] = (3, 'pink')
>>> x[0] = 4
TypeError: 'tuple' object does not support item assignment

If the tuple contains only one element, for example, the element is of string data type, then the tuple will not be considered as a tuple rather it will be considered as a string. See the example below:

>>> x = ("Python")
>>> print(type(x))
<class 'str'>

You can see here that the data type of x is str rather than tuple. To make it a tuple a trailing comma will be used as:

>>> x = "Python",
>>> print(type(x))
<class 'tuple'>

Access Tuple Elements

The elements of the tuple can be accessed by using any of the following ways:

Index

An index operator [] can be used to access elements of a tuple. The index of tuple starts from 0. If the index is not in range (item not defined at that index in the tuple), you will have an IndexError. It should be noted here that index must be an integer otherwise TypeError will occur.

>>> x = (3, 'pink', 3+8j)
>>> print(x[0])
3
>>> print(x[2])
(3+8j)

Negative Index

The same as Python list, you could use negative indexes to access tuple elements.

>>> l = (2, 4, 6, 8, 10)
>>> print(l[-1])
10
>>> print(l[-2])
8
>>> print(l[-3])
6

Slice

A slicing operator : is used to extract a range of elements from a tuple.

>>> l = (2, 4, 6, 8, 10)
>>> print(l[1:3])		#prints from location 1 to 3
(4, 6)
>>> print(l[:2])		#prints from the beginning to location 2
(2, 4)
>>> print(l[2:])		#prints elements from location 2 onwards
(6, 8, 10)
>>> print(l[:])		#prints entire list
(2, 4, 6, 8, 10)

Concatenate Tuples

Two tuples can be concatenated by using + operator.

>>> l = (2, 4, 6, 8, 10)
>>> print(l + (12, 14, 16)
(2, 4, 6, 8, 10, 12, 14, 16)

Delete a Tuple

The elements of a tuple cannot be deleted because tuples are immutable. But you can delete the entire tuple using the del keyword:

l = (2, 4, 6, 8, 10)
del l

Python Tuple Methods

Tuples have only two methods as tuples are immutable:

Tuple Built-In Functions:

Below are tuple built-in functions applicable to tuple to perform different tasks:

Tuple Membership Check

The in keyword checks if an item is a member of the tuple or not. See the code exaple below:

>>> l = (2, 4, 6, 8, 10)
>>> print(5 in l)
False
>>> print(2 in l
True

Iterate Through a Tuple

You can iterate through a tuple by using for loop:

l = (2, 4, 6, 8, 10)
for i in l:
    print(i)

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