- Python Introduction
- Python - Overview
- Python - History and Evolution
- Python - Significance in Modern Development
- Python - Understanding Python's design philosophy and the Zen of Python
- Python - Installing Python and Setting up the Development Environment
- Python - Setting Up the Development Environment
- Python - Basic Syntax and Execution of Python Scripts
- Python - Getting Started to Python
- Python Basics
- Python - Control flow (If statements, Loops - For and While)
- Python - Operators (Arithmetic, Comparison, Logical, Assignment)
- Python - Arithmetic Operators
- Python - Comparison Operators
- Python - Logical Operators
- Python - Assignment Operators
- Python - Integers (int)
- Python - Floats (float)
- Python - Strings (str)
- Python - Loop Control Statements
- Python - Loops
- Python - If Statements
- Python - Python's built-in functions
- Python - Using Built-in Functions
- Python - Examples of Common Built-in Functions
- Python Data Structures
- Python - Understanding Lists, Tuples, Sets, and Dictionaries
- Python - Lists
- Python - Tuples
- Python - Sets
- Python - Dictionaries
- Python - Operations on Data Structures (Indexing, Slicing, Appending, Removing)
- Python - Advanced Usage
- Python - Advanced Data Manipulation Techniques (List Comprehension, Dictionary comprehension)
- Python - List Comprehensions
- Python - Dictionary Comprehensions
- Python Functions and Modules
- Python - Defining a Function
- Python - Function arguments and return values
- Python - Function Arguments
- Python - Return Values
- Python - Defining and calling functions
- Python - Using the Return Value
- Python - Calling the Function with Arguments
- Python - Creating a Module
- Python - Importing a Module
- Python - Creating a Package
- Python - Importing from a Package
- Python - Creating and importing modules and packages
- Python - Introduction to Python standard libraries.
- Python - File and Directory Access
- Python - Internet Data Handling
- Python - Networking
- Python - Data Persistence and Serialization
- Python - Data Compression and Archiving
- Python - Concurrent Execution
- Python - Mathematics
- Python - Date and Time
- Python - Development Tools
- Python Object-Oriented Programming
- Python - Understanding classes and objects
- Python - Understanding Classes
- Python - Understanding Objects
- Python - Inheritance, encapsulation, and polymorphism
- Python - The constructor, class variables, and instance variables
- Python - Magic methods and their importance
- Python Error Handling and Debugging
- Python - Exceptions
- Python - Working Code Sample Demonstrating Both
- Python - Handling exceptions with try-except blocks
- Python - Syntax Errors versus Exceptions
- Python - Using logging for Debugging and Error tracking
- Python Working with Files
- Python - Reading from and writing to files
- Python - Writing to a File
- Python - Reading from a File
- Python - Combined Example of Reading and Writing
- Python - Understanding file handling modes
- Python - Common File Handling Modes
- Python - Working with different file formats (text, CSV, JSON)
- Python - Working with Text Files
- Python - Working with JSON Files
- Python - Working with CSV Files
- Python Web Scraping
- Python - Introduction to Beautiful Soup and requests library
- Python - Beautiful Soup
- Python - Requests Library
- Python - Legality of Web Scraping
- Python - Overview of web scraping and its legality
- Python - Combined Example: Using Both Requests and Beautiful Soup
- Python - Conclusion
Python - Magic methods and their importance
Magic Methods in Python
Magic methods in Python (also known as "dunder methods" because of the double underscores around their names) are special methods that enable arbitrary actions to be performed on objects. Allows you to teach yourself how your objects interact with Python's built-in functions and syntax, for example
- Arithmetic operations: __add__, __sub__, __mul__, etc.
- Comparison operations: __lt__, __eq__, __gt__, etc.
- Object representation: __str__, __repr__
- Attribute access: __getattr__, __setattr__, __delattr__
- Initialization and destruction: __init__, __del__
- Iteration: __iter__, __next__
- Container operations: __len__, __getitem__, __setitem__
Importance of Magic methods
Magic methods let you write more readable and Pythonic code by making your specific object act like a regular Python object. For example, you can specify how your object is printed by specifying __str__. We can use the + operator with your object by implementing __add__.
Example
In this example, we create a class "circle" to demonstrate the use of the magic methods:
import math
# define a circle class
class Circle:
def __init__(self, radius):
self.radius = radius
def __str__(self):
return f"Circle with radius {self.radius}"
def __repr__(self):
return f"Circle({self.radius})"
def __eq__(self, other):
return self.radius == other.radius
def __lt__(self, other):
return self.radius < other.radius
def __add__(self, other):
return Circle(self.radius + other.radius)
def __len__(self):
return int(self.circumference())
def circumference(self):
return 2 * math.pi * self.radius
#Creating Circle instances
circle1 = Circle(5)
circle2 = Circle(10)
#Demonstrating __str__ and __repr__
print(circle1)
print(repr(circle2))
#Demonstrating __eq__ and __lt__
print(circle1 == circle2)
print(circle1 < circle2)
#Demonstrating __add__
combined_circle = circle1 + circle2
print(combined_circle)
#Demonstrating __len__
print(len(circle2))Output
Circle with radius 5
Circle(10)
False
True
Circle with radius 15
62
Explanations
A radius is specified when using __init__ to initialize a Circle object.
The print() method is called __str__, which returns a string representation that is readable by humans.
For development and debugging purposes, __repr__ offers a clear text representation of the object. It is invoked by the method repr().
Two Circle objects can be compared with == thanks to __eq__.
Two Circle objects can have their sizes compared using \ by using __lt__.
By combining two Circle objects, __add__ allows the creation of a new Circle with the combined radius.
By returning the circumference rounded to the closest integer, the len() method can be used on a Circle instance thanks to __len__.
