Python Functions: The Best Guide for You

In computer programming, a “function” is a group of statements that work together to do a single task. Calling a function in Python is like breaking up a big block of code into smaller pieces or modules that are easier to work with and more helpful. Calling a function from different parts of a programme more than once is possible. Reusing the code is as easy as calling a function or code block already set up. This means that you don’t have to write the same code twice. Inside the class, you can set up all kinds of Python Functions, modules, nested functions, etc.

Thus, the word “function” in Python describes a piece of code written to carry out a specific task.

First;y, let us understand what Python Functions are.

What are Python functions? 

Python functions are groups of statements that, when run, do what you want. The goal is to put together tasks that are similar or that are done often into a single function. Then, you can use that function instead of writing the same code repeatedly for different inputs.

A Python function comprises three parts: def, the function name, and a colon (:).

Secondly, let us have a look at examples of Python Functions.

Python Functions Examples

Example #1

def greet():

    print(‘Hello Beautiful People!’)

# call the function


print(‘Outside function’)

Output: “Hello, Beautiful People!”

Example #2 – Python Code for User-Defined function  

def square( num ):    


    This function computes the square of the number.  


    return num**2     

object_ = square(9)    

print(“The square of the given number is: “, object_ )    

Output: The square of the given number is: 81

Moving forward, let’s discuss advantages of Python Functions.

Advantages of using Python Functions

Python Functions
  • Increases Code Reusability:  Since Python functions can be called as many times as needed, and code can be used more than once.
  • Functions help break up a complicated programme into chunks that are easier to read and easier to fix if something goes wrong.
  • Helping to make code more modular. With Python’s built-in functions, the user can break the programme into smaller pieces that can be worked on one at a time, which speeds up the development process.

Following this, here are different Python Functions to discuss.

Different Python Functions

Each Python programme comprises “functions,” which are separate sections of code that can be used in different situations and called as needed.

A function is something that is used to do a specific task. The function may need more arguments. When the task is done, the function may or may not give back a value.

The functions in Python can be put into two groups:

  • User-defined functions are ones that the user makes to get something done.
  • Python comes with several functions that can be used right away.
  • UDFs stand for “user-defined functions.

A programmer makes these functions so that they can be used for any task or to make solving big problems easier. These functions are then used as needed.

  • Built-in Functions

Python already has built-in functions that you can use. To use a specific function, the user must remember its name and the list of inputs it needs. Since the system already has these functions, it is unnecessary to define them again.

Next, let us explore what Python Lists are.

Python Lists: What Are They?

In Python, lists are the most fundamental and fundamentally standard container.

Lists in Python are ordered groups of objects that can be changed and have items of different types.

  • They are arranged in a way to suggest that there is some hierarchy at play.
  • Mutable indicates the list can be altered or changed.
  • Lists are different from each other so you can add different kinds of data, like integers, strings, and even other Lists, to a single collection.
  • A comma denotes each item in a list; the whole thing is enclosed in square brackets [].
  • A list is an iterable object. We can go through each item in a list using an iterative process.
  • Similar to arrays in languages like C++ and Java, lists can have varying sizes depending on the context.

Comparison of Python List Methods and List Functions

Passing parameters into a Python function is possible, but the function might not return anything. On the other hand, a method can be passed around as if it were an actual object instance, and the results may or may not be what you’d anticipate. They can be used as inputs to methods that perform actions on functions. That being said, not all functions may be viewed as methods in Python.

Python Function Arguments

When a function is called in Python, it receives a value known as an argument. People often confuse parameters with arguments, but the main difference is that parameters are variables used inside the curly brackets of a function. In contrast, it receives a value via a parameter called an argument.

Different Types of Function Arguments in Python

We can use function calls with Python’s four built-in function argument types to do many things. Here are some of them:

  • Python Parameters By Default
  • Using Python’s Keyword Arguments
  • Python’s Arbitrary Arguments
  • Python’s Required Arguments 

Now, let’s take it step by step and look at the different kinds of function arguments.

1. Python Default Arguments

Python’s default argument is used to define a parameter’s backup value. These kinds of parameters can be left out of a function call. The default value is used if no argument is given, and the argument value is used to replace the default value otherwise.

2. Python Keyword Arguments

In Python, functions can have optional arguments with names that can be given default values. Keyword arguments are those that are supplied to a function by its name. When using keyword arguments, the order in which function arguments are given does not depend on the order in which they were declared inside the function. When the function is called with no arguments, the default value will be used in its place.

3. Python Required Arguments

As the name suggests, required arguments must be given to the function when called. There will be a mistake if you don’t. Required arguments, in the simplest terms, are the polar opposite of default function parameters.

4. Python Arbitrary Arguments

Because Python supports arbitrary arguments, a function can take a list of ideas of arbitrary length that does not contain any keywords. Example – Copy Code.


Python is a high-level programming language that gives coders a lot of freedom. How a programmer uses different arguments in a function depends on what they want to do and how they like to work.

This blog explains the many Python functions and arguments related to lists. We started with a simple definition and looked at how some basic operations and protocols are put into place. Python functions are helpful whether you are a data analyst looking at datasets or a data scientist making machine learning models.

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