Reference library

OOP & classes

Classes, instances, methods, dataclasses, and object-oriented design in Python.

5 matches
OOP & classes medium

How to Create a Data Splitter Class in Python

This code defines a DataSplitter class that splits data by index, into chunks, or by a predicate, demonstrating OOP principles in Python.

class data-splitting slicing
Python 
class DataSplitter:
    def __init__(self, data):
        self.data = list(data)
    
    def split_by_index(self, index):
        return self.data[:index], self.data[index:]
    
    def split_into_chunks(self, chunk_size):
        return [self.data[i:i + chunk_size] for i in range(0, len(self.data), chunk_size)]
   …
14 0 Open
OOP & classes medium

How to Implement the Command Pattern with Undo in Python

Python code demonstrating the Command design pattern with undo and redo support using action objects and a history manager.

command-pattern design-patterns oop
Python 
class Command:
    def execute(self):
        raise NotImplementedError

    def undo(self):
        raise NotImplementedError


class AddTextCommand(Command):
    def __init__(self, document, text):
        self.document = document
        self.text = text

    def execute(self):
        self.document.append(self.tex…
13 0 Open
OOP & classes medium

Memento Pattern in Python: Save and Restore Object State

Implement the Memento design pattern to snapshot and restore an object's state, demonstrated with a text editor undo feature.

memento design-pattern undo
Python 
class TextEditor:
    def __init__(self, text="", cursor_pos=0):
        self.text = text
        self.cursor_pos = cursor_pos

    def type_text(self, new_text):
        self.text += new_text
        self.cursor_pos += len(new_text)

    def move_cursor(self, pos):
        self.cursor_pos = max(0, min(pos, len(self.t…
14 0 Open
OOP & classes medium

Understanding Multiple Inheritance Method Resolution Order in Python

This code demonstrates how Python's MRO determines which greet method is called in a diamond inheritance scenario, and prints the full MRO for class D.

multiple inheritance mro inheritance
Python 
class A:
    def greet(self):
        return "Hello from A"

class B(A):
    def greet(self):
        return "Hello from B"

class C(A):
    def greet(self):
        return "Hello from C"

class D(B, C):
    pass


if __name__ == "__main__":
    d = D()
    print(d.greet())
    print(D.__mro__)
12 0 Open
OOP & classes medium

Visitor Pattern in Python: Double Dispatch Demo

Demonstrates the Visitor design pattern with double dispatch so operations on Dog and Cat objects are selected at runtime without modifying their classes.

visitor-pattern design-patterns double-dispatch
Python 
class Animal:
    def accept(self, visitor):
        visitor.visit(self)

class Dog(Animal):
    def speak(self):
        return "Woof!"

class Cat(Animal):
    def speak(self):
        return "Meow!"

class SoundVisitor:
    def visit(self, animal):
        if isinstance(animal, Dog):
            return self.visit_do…
11 0 Open

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