Pop Function in Python

Last Updated on May 16, 2023 by Prepbytes

Python is a high-level programming language that has become incredibly popular over the years because of how easy and adaptable it is to use. It is an easy-to-learn object-oriented language that allows dynamic typing. Numerous functions and methods that are already included in Python make development easier. The ‘pop()’ method, which is used to remove an entry from a list, is one example of such a function.

We shall talk about the Python pop Function in this article. We shall examine its working, as well as its syntax, parameters, and return value. To further assist you in comprehending how to apply this technique, we’ll also look at some examples.

Pop() Function in Python

To remove an element from a list in Python, use the pop Function. It is a built-in function in Python that is typically used to delete the last entry from a list. The element can also be eliminated from any place in the list using this method, though.

Prior to exploring the pop() method, it’s critical to have a solid grasp of Python lists.

Understanding Lists in Python

In a single variable, lists are a type of data structure that are used to store several values. They can include any kind of data, including integers, texts, and even other lists, and are defined using square brackets.

For example, here’s how you can define a list in Python:

fruits = ['apple', 'banana', 'orange', 'mango']

Lists can have their elements added, removed, or modified since they are changeable. The pop() technique is useful in this situation.

Syntax of the Pop Function in Python

The pop function in Python has the following syntax:

list_name.pop(index)

Here, "list_name" denotes the name of the list from which you wish to delete an element, and "index" denotes the desired element’s desired index position. If you don’t give the method an index position, it will take the final element out of the list.

Parameters of the Pop Function in Python

The index position of the element you want to remove is the only optional argument for the pop method in Python. If you don’t give the method an index position, it will take the final element out of the list.

Return Value of the Pop Function in Python

The element that was deleted from the list is returned by Python’s pop function.

Working of the Pop Function in Python

The pop function in Python operates by returning an element after removing it from a list. The index position of the element you want to remove can be specified when calling the procedure. If the index is left blank when using the pop() function, the final element is eliminated.
The element at the supplied index position is removed from the list when the method is invoked. The element that was deleted is then returned by the method when the list has been updated.

Examples of Pop Function in Python

Let’s take a look at some examples to better understand how to use the pop Function Python:

Example 1: Removing the Last Element from a List

In this example, we’ll use the pop Function to get rid of the list’s last item.

fruits = ['apple', 'banana', 'orange', 'mango']
last_fruit = fruits.pop()


print(fruits) # Output: ['apple', 'banana', 'orange']
print(last_fruit) # Output: 'mango'

Output:

['apple', 'banana', 'orange']
mango

Explanation:
First, we define a list of "fruits" in the code above, which consists of four elements. The pop Function is then used on this list without an index point being specified. This retrieves the last element (the word "mango") from the list after removing it. Our ‘last_fruit’ variable serves as a repository for the returned value.

The eliminated element "last_fruit" is then printed along with the modified list "fruits." As you can see, the variable ‘last_fruit’ now has the value ‘mango’ and the element’mango’ is no longer present in the list ‘fruits’.

Example 2: Removing an Element from a Specific Position in a List

In this example, we will use the pop function python to remove an element from a specific position in a list.

fruits = ['apple', 'banana', 'orange', 'mango']
second_fruit = fruits.pop(1)


print(fruits) # Output: ['apple', 'orange', 'mango']
print(second_fruit) # Output: 'banana'

Output:

['apple', 'orange', 'mango']
banana

Explanation:
With an index point of 1, we call the Python pop Function on the list "fruits" in the code above. The "banana" element at index position 1 is removed and then returned. Our’second_fruit’ variable serves as a repository for the returned value.
Then, we print the revised list "fruits" along with the deleted item "second_fruit." As you can see, the variable ‘second_fruit’ now has the value ‘banana’ and the element ‘banana’ is no longer present in the list ‘fruits’.

Example 3: Passing Negative Indexes to the Pop Function in Python

Here’s an example code demonstrating the use of the pop function python with negative indexes:

my_list = ['apple', 'banana', 'cherry', 'orange', 'pineapple']


# Remove and return the last element in the list
last_element = my_list.pop()
print(last_element)  # Output: 'pineapple'


# Remove and return the second-to-last element in the list
second_last_element = my_list.pop(-2)
print(second_last_element)  # Output: 'orange'


# Print the modified list after removing elements
print(my_list)  # Output: ['apple', 'banana', 'cherry']

Output:

pineapple
cherry
['apple', 'banana', 'orange']

Explanation:
The example code creates a list called my_list with 5 elements. The final element in the list, "pineapple," is then removed using the pop() method. The next step is to delete and return the second-to-last member in the list, "orange," using the pop() function and a negative index. The updated list, which now only has three elements, is then printed after the elements have been removed.

Differences between Pop() and Remove() Methods

The distinction between the remove() method and the pop() method must be made. There are some distinctions between the two techniques, despite the fact that they are both used to delete items from a list.

• An entry can be deleted from a list by giving its index position and using the pop() method. The list is updated and the eliminated element is returned. The last element in the list is removed by the procedure if no index position is supplied.
• By giving its value, the remove() method can be used to remove an element from a list. The list is updated, and it returns nothing. The method raises a ValueError if the requested value cannot be found in the list.

Here is an example that demonstrates the difference between the two methods:

fruits = ['apple', 'banana', 'orange', 'mango']


# Using pop() method
removed_fruit = fruits.pop(1)
print(removed_fruit) # Output: 'banana'
print(fruits) # Output: ['apple', 'orange', 'mango']


# Using remove() method
fruits.remove('orange')
print(fruits) # Output: ['apple', 'mango']

Output:

banana
['apple', 'orange', 'mango']
['apple', 'mango']

Explanation:
In the code above, we first use the pop() method to remove the element (‘banana’) at index position 1 and save it in the variable ‘removed_fruit’. The removed element "removed_fruit" and the revised list "fruits" are then printed.

The element "orange" is then taken out of the list "fruits" using the remove() method. You can see that the list ‘fruits’ is changed to delete the element ‘orange’ and that the remove() method does not return anything.

Conclusion
The pop Function Python and how to use it to remove elements from a list have been covered in this article. We have also looked at various examples that use the pop() method to show how to use it. Python’s pop() function is a fantastic resource for working with lists. It gives you a quick and easy way to eliminate items from a list without having to manually reassign it.

In conclusion, the pop() method in Python is a useful tool for manipulating lists. Any Python programmer should learn and comprehend this approach because it may be applied to a variety of tasks.

Frequently Asked Questions (FAQs)

Q1. How does the Pop Function work?
Ans. The Pop function takes an argument that specifies the index or key of the element to remove from the list or dictionary. If the argument is not provided, the function removes and returns the last element from the list. If the specified index or key is not found in the list or dictionary, the function raises a KeyError.

Q2. What is the syntax for using the Pop Function in Python?
Ans. The syntax for using the Pop function is as follows:

For a list: list_name.pop(index)
For a dictionary: dict_name.pop(key[, default])

Q3. What is the difference between using the Pop Function and the Del statement in Python?
Ans. The Pop function and the Del statement both remove elements from a list or dictionary. However, the Pop function also returns the removed element or value, while the Del statement does not. Additionally, the Del statement can be used to remove multiple elements from a list or dictionary at once, while the Pop function only removes one element at a time.

Q4. Can the Pop Function be used on an empty list or dictionary?
Ans. No, attempting to use the Pop function on an empty list or dictionary will result in an IndexError or KeyError.

Q5. Are there any other arguments that can be passed to the Pop Function in Python?
Ans. For a dictionary, the Pop function can also take a default argument that specifies the value to return if the specified key is not found in the dictionary. If the default argument is not provided and the key is not found, the function raises a KeyError.