Python Functions: Definition, Types, and Examples

 

 ✍️Introduction

In Python, a function is a block of code that performs a specific task.

Functions help us reuse code, reduce repetition, and make programs easy to understand.

In this article, you will learn:

• What Python functions are

• How to create and use functions

• Types of functions

• Simple examples

What is a Function in Python?

A function is a named block of code that runs when it is called.

Python uses the def keyword to define a function.

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🧑‍💻 Syntax of Python Function

def function_name():
    statement


Example of a Simple Function
def greet():
    print("Hello, welcome to Python")

Calling the Function
greet()


1️⃣ Function with Parameters
Parameters are values passed to a function.
Example:

def add(a, b):
    print(a + b)

add(5, 3)

2️⃣ Function with Return Value
The return statement sends a value back to the caller.
Example:
def square(num):
    return num * num

result = square(4)
print(result)

3️⃣ Types of Functions in Python
🔹 Built-in Functions
Already available in Python.

Examples:
print()
len()
type()
input()
🔹User-Defined Functions
Functions created by users.

Example:
def welcome():
    print("Welcome User")

4️⃣ Default Arguments
A function parameter can have a default value.
Example:
def greet(name="User"):
    print("Hello", name)

greet()
greet("Tushar")

5️⃣ Keyword Arguments
Arguments passed using parameter names.
Example:
def student(name, age):
    print(name, age)

student(age=20, name="Rahul")

6️⃣ lambda Function (Short Function)
A lambda function is a small anonymous function.
Example:
square = lambda x: x * x
print(square(5))

🎯 Why Functions are Important?
Code reusability
Easy debugging
Better readability
Saves time
Important for exams & interviews

Real-Life Example
def check_even(num):
    if num % 2 == 0:
        return "Even"
    else:
        return "Odd"

print(check_even(10))

❌ Common Mistakes
Forgetting indentation
Not calling the function
Wrong parameter count

Conclusion
Functions make Python programs organized, reusable, and powerful.

Understanding functions is essential to become a good Python programmer.
Practice creating functions daily to improve your skills.

💬 Let’s Interact!
Write a function to print your name.

Comment your function code below 👇😊

📌 Related Articles:
Python Loops
Python Conditional Statements
Python Operators