OOP & classes
Classes, instances, methods, dataclasses, and object-oriented design in Python.
Composition over Inheritance: How to Build a Wallet Account in Python
Demonstrates composition by wrapping a WalletAccount class in an AuditedWallet decorator-like class to add behavior without changing the original class.
class WalletAccount:
def __init__(self, owner, balance=0.0):
self.owner = owner
self.balance = balance
def deposit(self, amount):
if amount <= 0:
raise ValueError("Deposit must be positive")
self.balance += amount
return self.balance
def withdraw(self, …Group Data Helper Class in Python
A simple Python class that stores items under named groups, retrieves groups, items, and counts, and formats them as a readable summary.
class GroupData:
"""A simple helper class to store and group data for beginners."""
def __init__(self):
self.items = []
def add(self, item, group):
"""Add an item under a given group name."""
self.items.append({"item": item, "group": group})
def get_groups(self):
"""R…How to Build a Data Helper Class in Python with OOP
Create a beginner-friendly Python class that loads CSV data, filters records by field, and counts entries using object-oriented programming.
class DataHelper:
"""A beginner-friendly OOP helper for handling simple datasets."""
def __init__(self, filename):
self.filename = filename
self.data = self._load_data()
def _load_data(self):
"""Load data from a CSV file into a list of dictionaries."""
import csv
…How to Count Items in a Python Class
A beginner-friendly Inventory class that stores item quantities in a dictionary and provides add, remove, count, and summary methods.
class Inventory:
def __init__(self):
self.items = {}
def add(self, item, quantity=1):
self.items[item] = self.items.get(item, 0) + quantity
def remove(self, item, quantity=1):
if item not in self.items:
raise ValueError(f"{item} not in inventory")
self.items[it…Browse by section
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OOP & classes — Python code examples
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This page collects oop & classes snippets — short, copy-ready Python you can paste into our free online IDE and run without installing anything. Each sample includes a plain-English explanation and the full source code.
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