Skip to main content

Functions in Python

 

Learning Sections     show

Functions in Python

Functions in Python are reusable blocks of code that perform a specific task. They help in organizing code into manageable sections and avoid repetition. Functions are defined using the def keyword followed by the function name and parentheses ().

Defining a Function

A function is defined using the def keyword. Here's a simple example of a function that takes a parameter and prints a greeting message:


# Defining a function
def greet(name):
    # Function body
    print("Hello, " + name + "!")

# Calling the function
greet("Alice")  # Output: Hello, Alice!

Return Statement

The return statement is used to return a value from a function. If no return statement is used, the function returns None by default.


# Function with return statement
def add(a, b):
    return a + b

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

Default Arguments

Functions can have default argument values, which are used if no value is provided when the function is called.


# Function with default arguments
def greet(name, message = "Hello"):
    print(message + ", " + name + "!")

# Calling the function
greet("Alice")  # Output: Hello, Alice!
greet("Bob", "Good morning")  # Output: Good morning, Bob!

Variable-Length Arguments

Functions can accept a variable number of arguments using the *args and **kwargs syntax.


# Function with *args
def sum_all(*args):
    total = 0
    for num in args:
        total += num
    return total

# Calling the function
result = sum_all(1, 2, 3, 4)
print(result)  # Output: 10
    

# Function with **kwargs
def print_info(**kwargs):
    for key, value in kwargs.items():
        print(f"{key}: {value}")

# Calling the function
print_info(name="Alice", age=25, city="Wonderland")

Lambda Functions

Lambda functions are small anonymous functions defined using the lambda keyword. They are useful for short, throwaway functions.


# Lambda function
square = lambda x: x ** 2

# Using the lambda function
print(square(5))  # Output: 25
Labels:

Popular posts from this blog

Introduction to OOPs in Python

  Learning Sections          show Introduction to Object-Oriented Programming (OOP) Object-Oriented Programming (OOP) is a programming paradigm that organizes software design around objects rather than actions and data rather than logic. It revolves around the concept of "objects", which are instances of classes. These objects encapsulate data, in the form of attributes or properties, and behaviors, in the form of methods or functions. OOP promotes modularity, reusability, and extensibility in software development. Key Concepts of OOP: Class: A class is a blueprint or template for creating objects. It defines the attributes (data) and methods (functions) that will characterize any object instantiated from that class. Object: An object is an instance of a class. It is a concrete realization of the class blueprint, containing actual values instead of placeholders for attributes. Encapsulation: Encapsulation is ...
Read more

Inheritance in Python

  Learning Sections          show Inheritance in Python Inheritance is a fundamental concept in object-oriented programming (OOP) that allows a class to inherit attributes and methods from another class. The class that inherits is called the child class or subclass, and the class being inherited from is called the parent class or superclass. Basic Inheritance In Python, a child class inherits from a parent class by specifying the parent class in parentheses after the child class name. Example: class Animal : def __init__ ( self , name ): self . name = name def speak ( self ): raise NotImplementedError ( "Subclass must implement this method" ) class Dog ( Animal ): def speak ( self ): return "Woof!" class Cat ( Animal ): def speak ( self ): return "Meow!" # Create instances of Dog and Cat dog = Dog ( "Buddy" ) cat = Cat ( "Whiskers" ...
Read more

read(), readlines() and other methods in Python

Learning Sections          show read(), readlines() and Other Methods in Python Python provides several methods to read from and manipulate files. Here are some common methods: 1. read() The read() method reads the entire content of a file and returns it as a string. # Open the file in read mode with open ( 'example.txt' , 'r' ) as file : # Read the entire content of the file content = file . read () print ( content ) 2. readlines() The readlines() method reads all the lines of a file and returns a list where each element is a line in the file. # Open the file in read mode with open ( 'example.txt' , 'r' ) as file : # Read all lines of the file lines = file . readlines () for line in lines : print ( line . strip ()) # strip() removes the newline character 3. readline() The readline() method reads one line from the file and returns it as a...
Read more