List append() Method in Python Explained with Examples

Chirag Goyal 01 Feb, 2024 • 9 min read

Introduction

The append() method in Python resides within the list class, offering ingenious functionality that streamlines the addition of items to lists and introduces flexibility, significantly enhancing program efficiency. Join us as we delve into the nuances of the append() method, exploring its diverse applications. Whether you’re a novice or a seasoned developer, this article guarantees valuable insights into maximizing the potential of append() in Python.

So let’s get started and take a closer look at the append() method in Python!

List Collection Type

In Python, one of the most common and useful data types is a list, which is basically a collection data type that allows storing a collection of items in a single variable. This is similar to arrays, but the main difference is that array can only store elements of the same data type, whereas List can also store heterogeneous elements.

Properties of List Collection Type in Python

This data type possesses the following key properties:

  • Lists maintain order, are changeable, and permit duplicate values.
  • They exhibit remarkable versatility, finding application in various programming scenarios.

Now, let’s delve into the append() method, a crucial operation within this extensive collection, and discuss its role.

To understand the List methods, refer to one of the beginner-level articles from Analytics Vidhya.

Role of the Python List Append Method

  • It is a built-in function that is used to add an item to the end of a list.
  • It is a common and powerful method for modifying lists in terms of elements and updating the same variable itself.
  • It allows you to easily add new elements to a list without creating a new list each time.

Advantage of the Append Method

One of the main advantages of this method, which we can directly find from its implementation, is that it allows you to build lists in a dynamic fashion instead of a static one, which helps us to add the items to the list, which is particularly useful when we don’t know how many items we have to add to the list in advance.

Overall, the append() method is an essential tool for working with lists in Python, and mastering it will help you become a more efficient and effective programmer.

Append Method in Python

In Python, the append() method is a built-in function used to add an item to the end of a list.

The append() method is a member of the list object, and it is used to modify the contents of an existing list by adding a new element to the end of the list. The append () method returns nothing.

How append works?
Source: Real Python

With the help of this method, we have to provide a simple function call to an existing list object and pass in the new item, which we have to add to the end of the list as an argument.

Every time we call this method on any existing list, this method adds a new item to the end of the list. You can refer to the link to learn more about the append method.

Syntax of the append() Method

The append() method appends an element to the end of the list.

Syntax:

list.append(element_to_be_added)

The parameter used in this method is shown below:

Parameter: element_to_be_added

Description: This parameter is required for this method which may be an element of any data type (string, integer, float, object, etc.).

Therefore, we can see that this method takes a single argument, basically the item we must add to the end of the list. Calling this method on a list adds the specified item to the end, consequently increasing the list’s length by one.

Top 10 Examples of Append Method in Python

Now, let’s see how we can use this append method as iterables or iterators to do the following functionalities. In all the following examples, we utilize Python 3, a language widely employed in technologies such as:

  • Data Science,
  • Machine Learning,
  • Deep learning, etc.

Other programming languages like Java, JavaScript, etc., can implement similar functionalities to these methods. Some Python libraries include:

  • Numpy for Matrix Manipulations,
  • Pandas for Data Analysis using Pandas DataFrame,
  • Matplotlib for Data Visualisation,
  • Tensorflow for Computer Vision,
  • NLTK for Natural Language Processing, etc.

Example 1: Pushing a Single Item to a List

In this example, observe a list of fruits where we attempt to add a new fruit, signifying the addition of a single element to the existing list and consequently increasing its length by one. This method does not have an associated return value.

# Created a list 

fruits = ["grapes", "banana", "cherry", "orange"]

# Add a new element to the list of the above fruits

fruits.append("apple")

# Print the updated list

print(fruits)

The output of the above program is shown below:

["grapes", "banana", "cherry", "orange", "apple"]

Example 2: Pushing Multiple Items to a List Using a For Loop

In this example, you can see that we have a list of fruits, and we are trying to add some new fruits to the existing list, increasing the list’s length by the length of the new list. Also, the list is created with the help of square brackets, or we can also create it through list comprehension.

# Created a list 

fruits = ["apple", "banana", "cherry"]

# Created a new list of fruits name

new_fruits = ["orange", "kiwi", "grape"]

# Looping over the list using For Loop to add elements

for fruit in new_fruits:
    fruits.append(fruit)

# Print the updated list

print(fruits)

The output of the above program is shown below:

["apple", "banana", "cherry", "orange", "kiwi", "grape"]

Example 3: Pushing a List to Another List

In this example, you can see that we have a list of integers, and we are trying to add a new integer list to the existing list, increasing the list’s length and creating a nested list. This means we are doing list concatenation.

# Created a list 

list1 = [1, 2, 3, 4, 5]

# Created a list 

list2 = [4, 5, 6, 7, 8]

# Apply append function

list1.append(list2)

# Print the updated list

print(list1)

The output of the above program is shown below:

[1, 2, 3, 4, 5, [4, 5, 6, 7, 8]]

Example 4: Pushing a List to Another List Using the extend() Method

As in the previous example, while using the append function, we have observed that due to the append() method, we are able to add the new list completely, but not in a separate manner, i.e., each element-wise, so to implements that tasks, In this example, we have taken a list of fruits.

 Source: Codingem.com
Source: Codingem.com

We are trying to add a new integer list to the existing list, increasing the list length we have to add. (list.extend)

# Created a list 

list1 = [1, 2, 3, 9, 10]

# Created a list 

list2 = [4, 5, 6, 1, 8]

# Apply to extend function instead of append

list1.extend(list2)

# Print the updated list

print(list1)

The output of the above program is shown below:

[1, 2, 3, 9, 10, 4, 5, 6, 1, 8]

Example 5: Pushing a Python Tuple to a List

In this example, you can see that we have a list of fruits and are trying to add a new fruit tuples data storage in the existing list. We can easily observe that inside the list other than string, we have tuples of string that can easily be added at the end of the list.

# Created a list 

fruits = ["apple", "banana", "cherry"]

# Created a Tuple 

my_tuple = ("orange", "kiwi", "grape")

# Apply append function

fruits.append(my_tuple)

# Print the updated list

print(fruits)

The output of the above program is shown below:

["apple", "banana", "cherry", ("orange", "kiwi", "grape")]

Example 6: Pushing a Python Dictionary to a List

In the previous example, we add the tuple to an existing list. Still, in this, we will add one dictionary corresponding to the key value type of data structure, and the operation can be easily done. Also, observe that there are different types of elements according to the data type in the list. The indicated list can be heterogeneous, which means it can store elements of different data types.

# Created a list 

fruits = ["apple", "banana", "cherry"]

# Created a Dictionary to add 

my_dict = {"orange": 1, "kiwi": 2, "grape": 3}

# Apply append function

fruits.append(my_dict)

# Print the updated list

print(fruits)

The output of the above program is shown below:

["apple", "banana", "cherry", {"orange": 1, "kiwi": 2, "grape": 3}]

Example 7: Pushing an Integer to a List

In this example, you can see that we have a list of integers, and we are trying to add a new integer in the existing list, increasing the list’s length by one.

# Created a list 

numbers = [1, 2, 3]

# Apply append function

numbers.append(4)

# Print the updated list

print(numbers)

The output of the above program is shown below:

[1, 2, 3, 4]

Example 8: Pushing a Python String to a List

In this example, you can see that we have a list of names of people, and we are trying to add a new person’s name to the existing list, increasing the list’s length by one. Only the thing is that the element which we have to add here is the string data type.

# Created a list 

names = ["Alice", "Bob", "Charlie"]

# Apply append function

names.append("David")

# Print the updated list

print(names)

The output of the above program is shown below:

["Alice", "Bob", "Charlie", "David"]

Example 9: Pushing a Python Boolean to a List

In this example, you can see that we have a list of booleans, and we are trying to add a new boolean value to the existing list, increasing the list’s length by one. Only the thing is that the element we have to add here is the boolean data type means the value is either True or False.

# Created a list 

flags = [True, False]

# Apply append function

flags.append(True)

# Print the updated list

print(flags)

The output of the above program is shown below:

[True, False, True]

Example 10: Pushing a None Value to a List

In this example, you can see that we have a list of integers, and we are trying to add a None value to the existing list, increasing the list’s length by one. Only the thing is that the element we have to add here is the None data type which means nothing.

# Created a list 

values = [1, 2, 3]

# Apply append function

values.append(None)

# Print the updated list

print(values)

The output of the above program is shown below:

[1, 2, 3, None]

These examples demonstrate the versatility and power of the append() method in Python and show how it can be used to add a wide range of items to lists differently.

Conclusion

In conclusion, we can say that the append() method in Python programming language is a very powerful tool for adding new elements to an existing list. As we’ve observed in this article, it’s incredibly easy to use and can be used in a variety of different situations. Whether you’re working with a small or large list, the append() method can help you quickly add new items to your collection.

To illustrate the power of the append() method, we have discussed one of the stories. We can easily append the new items to the list by writing a few program lines.

  • Regarding space complexity, we don’t have to create a new structure to store the updated list; we can utilize the initial list. In this way, we can say that this method is memory efficient.
  • Also, we can add any data type to an existing list, which means the list can work for elements of the different data types.

Therefore, this append() method in Python is an essential tool that can help you quickly and easily add new elements to your list. Overall, the append() method is a powerful and essential tool for working with lists in Python, and it is used extensively in many different programming applications.

Frequently Asked Questions

Q1. Is Append a python built-in function?

A. Yes, append() is a built-in method in Python that belongs to the list collection type or class. This is used to add an item to the end of a list.

Q2. What is the difference between Append and Concat?

A. The append function will add new elements in the existing list iteratively one by one. In contrast, the Concat function will do a single operation to finish the job, i.e., directly add those elements in one iteration, which makes it faster than append().

Q3. What is the opposite of Append in python?

A. The opposite of append in Python is list. pop(index) removes and returns the element at the given index. Basically, this returns the rightmost element if the index is omitted, which can be considered roughly the opposite of append().

Q4. What is the python Append function used for?

A. It’s a built-in function that appends items to a list’s end, facilitating efficient modification without creating a new list each time. Ideal for seamlessly updating and extending existing lists.

Q5. Is Append the same as += in python?

A. The append() method adds elements to the list by utilizing a mutator() method, whereas the ‘+’ operator creates a new list with the capacity for one more element.

Chirag Goyal 01 Feb 2024

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