Exploring Advanced Python Concepts: class methods, static methods, decorators, and singletons

Introduction

As I explored deeper into Python, I studied four powerful and sometimes confusing concepts:

• Class Methods
• Static Methods
• Decorators
• The Singleton Pattern

Here’s a summary of what I learned, what I struggled with, and how I plan to use these ideas going forward.

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Class Methods

Class methods are defined with @classmethod and take cls instead of self. I learned they are useful for:

• Creating alternative constructors
• Modifying class-level data
• Acting as factory functions

What was tricky: Understanding the difference between cls and self, and when to use class methods over instance methods.

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Static Methods

Static methods use @staticmethod and do not take self or cls. They’re just plain functions inside a class.

Use case: When a method logically belongs to a class but doesn’t need access to instance or class data.

What was tricky: I thought static methods could still access instance variables — they can’t.

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Decorators

Decorators wrap a function to modify its behavior. I created a decorator that logs function inputs and outputs.

def logger(func):
    def wrapper(*args, **kwargs):
        print("Calling", func.__name__)
        result = func(*args, **kwargs)
        print("Returned", result)
        return result
    return wrapper

What was tricky: The idea of functions returning functions was hard to grasp at first. Also, keeping track of the *args, **kwargs syntax.

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Singleton Pattern

A singleton ensures a class has only one instance. I implemented this pattern in Python using a class variable to store the instance.

Why it matters: Useful for shared resources like database connections or configuration.

What was tricky: Avoiding multiple initializations and understanding how __new__ or class-level flags work to enforce the singleton.

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What I learned

• Python has a lot of powerful tools for organizing logic
• Decorators and static methods helped me clean up repeated code
• Understanding class-level vs instance-level concepts is essential

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What I want to do next

• Use class methods in real project initializations
• Apply decorators to log or secure API functions
• Explore design patterns like Factory and Observer
• Build a settings manager using the Singleton pattern

These concepts take time to sink in — but they’re exactly what separates beginner code from scalable, professional code.