What the hell are functions in Python | TechAmbitionX | An easy guide by Mr. BILRED

What the hell is a Function in Python?

Okay relax, you might've not opened the book, and exam is around the corner, but still, there's hope. HOPE!

What is a Function?

A function is a reusable block of code that performs a specific task. Functions help you organize code, avoid repetition, and make programs easier to understand. Got it?

Creating Functions with def

def greet():
    print("Hello, TechAmbitionX!")

This defines a function named greet. To use it, call it like this:

greet()  # Output: Hello, TechAmbitionX!

Returning Values with return

Functions can return values instead of printing them. This makes your code more flexible.

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

result = add(5, 3)
print(result)  # Output: 8

print() vs return

• print() displays output immediately.
• return sends data back to where the function was called, so you can store or use it later.

Okay, maybe upar se gai, but wait;
Use print() to see the result. Use return to use the result.

Positional vs Keyword Arguments

Functions accept inputs called arguments. You can pass them by position or by naming the parameters explicitly.

def info(name, age):
    print(f"{name} is {age} years old.")

info("Bilal", 22)  # Positional arguments
info(age=22, name="Bilal")  # Keyword arguments

Default Parameter Values

You can set default values for parameters. If an argument is not provided, the default is used.

def greet(name="TechAmbitionX"):
    print(f"Hello, {name}!")

greet()          # Output: Hello, TechAmbitionX!
greet("Bilal")   # Output: Hello, Bilal!

Functions Taking Input & Returning Output

Functions often accept inputs and return outputs to be used elsewhere in your program.

def square(num):
    return num * num

print(square(4))  # Output: 16

🔄 Nested and Recursive Functions

Nested functions are functions inside functions:

def outer():
    def inner():
        print("Hello from inner function!")
    inner()

outer()

Recursive functions call themselves to solve problems step-by-step:

def factorial(n):
    if n == 0:
        return 1
    else:
        return n * factorial(n-1)

print(factorial(5))  # Output: 120

The above example may cause a small headache to understand, but I'll leave it that way so you may work on that(InshaALLAH that understanding would help ya). Hint: Recursive Function keeps calling itself with a smaller or simpler value until it reaches a point where it stops called the base case.

Lambda Functions (Anonymous Functions)

Lambda functions are short, unnamed functions useful for simple tasks:

square = lambda x: x * x
print(square(6))  # Output: 36

Quick Recap

Concept	Example
Define Function	def func(): ...
Return Value	return value
Print vs Return	print() shows output, return sends data back
Arguments	Positional & Keyword
Default Params	def func(x=5): ...
Nested Functions	Functions inside functions
Recursive Functions	Functions calling themselves
Lambda	Anonymous short functions

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OKAY, NOW DONT RUN AWAY NOW, TRY YOUR CODES HERE OR AT YOUR CODE EDITOR... PROGRAMMING SIRAF DEKHNEY SE HI NAHI AAJATI(I Can't Much about this something, but that's what they say), DO PRACTICE

This post is for educational purposes only.

What I Think:
KNOWLEDGE SHOULD BE SHARED ONLY WITH THE ONE, WHO KNOWS ITS TRUE WORTH. Not everyone deserves it. - Bilal Ahmad Khan AKA Mr. BILRED