Python is a widely used, high-level, general-purpose programming language, particularly suited for developing GUI and web applications. It is also a very attractive choice for application development because it offers dynamic typing and binding options. In this article, we will be learning about an important data structure in Python programming: tuples.
What Is Python?
Python is a powerful, high-level, easy-to-learn programming language. Thanks to outstanding characteristics such as object-oriented, open-sourced, and having numerous IDE’s, it is one of the most in-demand programming languages in today’s IT industry. One of Python’s main advantages is that it provides excellent library support and has a large developer community. Python also provides easy integration with web services and GUI-based desktop applications.
Introduction to Python Tuples
A Python tuple is an immutable ordered sequence of items. In other words, existing objects in the sequence cannot be modified, and new elements cannot be added once the sequence is created. A tuple consists of several values separated by commas. Unlike a Python list, tuples are enclosed within parentheses “( )”.
How to Create a Python Tuple
A Python tuple is created by using parentheses separated by commas. A tuple can hold multiple data types.
Syntax: tuple_name = (“element1”, “element2”, “element3”)
Example:
Fig: Creating a Python Tuple
Nested Python Tuples
We can also nest a tuple or a list inside a Python tuple. The below-mentioned example illustrates this.
Example:
Fig: Nested tuple
We can see the type of class being used by employing the type() method.
Fig: To know the type of class in a tuple
How to Access Items From a Tuple
We can access a tuple’s elements by referring to the index number. Remember that the index in a Python tuple starts from ‘0’. To access elements in a tuple, we provide the index (as integer) inside the square brackets ( [ ] ), as shown below.
Fig: Access item from a tuple
To access the elements from the end of the tuple, we use negative indexing. So, -1 means the last element, -2 the second last element, and so on.
For example: If we want to access the 4th element from the end of the tuple named ‘city’, we write city[-4].
Fig: To access an element from the end of a tuple
We can also access the elements from a specific range.
Syntax: tuple_name[starting index : ending index]
Fig: To access elements within a specific range in a tuple
Remember that the first item is position 0.
Note: The search will start at index 1 (included) and end at index 4 (not included)
If we leave out the starting value, the range will begin from 0th index. Example:
Fig: To access elements from 0th index
Nested tuples are accessed using nested indexing, as shown in the example below.
Fig: To access elements inside a nested tuple
Different Tuple Operations
Let’s take a look at a selection of tuple operations.
How to change and add elements to the tuple
We cannot add or change the item in a tuple once it is created. Any attempt to do so produces an error message. The following example illustrates the point.
Fig: Error message when attempting to change a tuple
Fig: Error message trying to add elements to a tuple
But there is a trick. You can convert a tuple into a list, add or modify the element, then change it back to a tuple, as the following example illustrates.
Fig: Modify an element in a tuple
In the example above, we first converted the tuple ‘city’ into a list with the name ‘newcity’. Now we can change the element value by specifying the index number and replacing it with a new element. Then we converted the list ‘newcity’ back to tuple ‘city’.
Similarly, we can add the element in a tuple. For this, we use the append () method.
Fig: To add an element in a tuple
We can also change the element of a list inside a tuple.
Syntax: tuple_name [index of list in the tuple] [index of element inside a list]
Example:
Fig: To modify a list inside a tuple
Now that we know how to create and access items from tuples, let’s move on and see how to add and delete elements from tuples.
How to Delete Elements From a Tuple
There are limitations when it comes to deleting in Python tuples. We cannot delete items directly from a tuple; this results in an error message. This happens because the remove() method is not a tuple attribute.
Fig: Error message when trying to delete an element from a tuple
How to Check for an Item Existing in Tuple
We can check to see if a particular item exists in a tuple. The example below shows how it can be done.
Syntax: if “element_name “ in list_name :
Fig: To check if item exists in the tuple
How to Check the Length of a Tuple
You check the length of the tuple by using the len() method.
Syntax: print(len(tuple_name))
Example:
Fig: To check the length of a tuple
How to Join Two Tuples
You can join two tuples by using the ‘+’ operator.
Syntax: tuple_1 + tuple_2
Example:
Fig: To join two tuples
A Selection of Tuple Methods
Python supports a range of useful in-built methods that can be used inside a tuple.
Here are some examples of these functions:
- count()
The count() method returns the number of times a specified value has occurred in a tuple.
Syntax: print(tuple_name.count(“element”))
Example:
Fig: count() method in a tuple
- index()
The index() method returns the position of the specified element.
Syntax: print(tuple_name.index(“element”))
Example:
Fig: index() method in a tuple
- min()
The min() method returns the minimum value in a numerical tuple.
Fig: min() method in a tuple
- max()
The max() method returns the maximum value in a numerical tuple.
Fig: max() method in a tuple
- sum()
The sum() method adds all the values in a numerical tuple.
Fig: sum () method in a tuple
The Differences Between Lists and Tuples
List |
Tuple |
It’s mutable |
It’s immutable |
Lists come in variable lengths |
Tuples are fixed length |
Lists consume more memory |
Tuples consume less memory |
List operations are more error-prone |
Tuple operations are safe |
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Conclusion
Python tuples are very convenient for constructing and accessing individual elements in programming. To learn more about Python tuples, visit the link: https://m.youtube.com/watch?v=wRC4H-k57eg.
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