OOP &amp; classes

from dataclasses import dataclass, field
from typing import Any

@dataclass(order=True)
class Person:
    name: str = field(compare=False)
    age: int
    height_cm: float
    priority: int = field(compare=False, default=0)

    def __repr__(self):
        return f"Person(name={self.name!r}, age={self.age}, height={s…

class data-splitting slicing

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 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)]
   …

dataclass immutable money

OOP & classes easy

How to Create an Immutable Money Class in Python with dataclasses

Define a frozen dataclass Money that holds an amount and currency, enforces non-negative amounts, and supports safe addition across matching currencies.

from dataclasses import dataclass


@dataclass(frozen=True)
class Money:
    amount: float
    currency: str = "USD"

    def __post_init__(self) -> None:
        if self.amount < 0:
            raise ValueError("amount must be non-negative")

    def add(self, other: "Money") -> "Money":
        if self.currency != o…

16 0 Open

OOP & classes easy

How to Sort Data in Python with a Class Helper

This beginner-friendly class wraps the built-in sorted() function to sort numbers, strings ignoring case, and dictionaries by a specified key.

oop sorting sorted

class DataSorter:
    def __init__(self, data):
        self.data = data

    def sort_numbers(self, reverse=False):
        return sorted(self.data, reverse=reverse)

    def sort_strings_ignore_case(self, reverse=False):
        return sorted(self.data, key=str.lower, reverse=reverse)

    def sort_dicts_by_key(self…

How to Use slots in Python Classes for Memory Efficiency

Defines classes with __slots__ to prevent dynamic attribute creation and reduce memory usage, including inheritance with additional slots.

slots oop memory

classes dictionaries merging

```python
class Person:
    __slots__ = ("name", "age")

    def __init__(self, name: str, age: int):
        self.name = name
        self.age = age

    def greet(self) -> str:
        return f"Hi, I'm {self.name} and I'm {self.age} years old."


class Employee(Person):
    __slots__ = ("role",)

    def __init__(se…

13 0 Open

OOP & classes easy

How to merge dictionaries by a key in Python with a class

This code defines a DataMerger class that collects dictionary records and merges them by a specified key, combining fields from multiple records with the same key.

class DataMerger:
    def __init__(self):
        self.records = []

    def add_record(self, record):
        if isinstance(record, dict):
            self.records.append(record)
        else:
            raise TypeError("Record must be a dictionary")

    def merge_by_key(self, key):
        merged = {}
        for …

13 0 Open

Python Abstract Class with Concrete Subclasses

Define an abstract base class with abstract methods and implement them in concrete subclasses like Rectangle and Circle.

abc abstract-methods oop

from abc import ABC, abstractmethod

class Shape(ABC):
    @abstractmethod
    def area(self):
        pass

    @abstractmethod
    def perimeter(self):
        pass

class Rectangle(Shape):
    def __init__(self, width, height):
        self.width = width
        self.height = height

    def area(self):
        ret…

template-method abstract-class design-pattern

Template Method Pattern in Python: Define Base Class with Algorithm Steps

Create a template method base class using ABC that defines the skeleton of an algorithm while letting subclasses implement specific steps.