OOP & classes
Classes, instances, methods, dataclasses, and object-oriented design in Python.
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 Create a Data Helper Class in Python with OOP
A complete OOP example with User, Post, and Blog classes that manage data relationships and provide clear helper methods.
class User:
def __init__(self, name, email):
self.name = name
self.email = email
self.posts = []
def create_post(self, title, content):
post = Post(title, content, self)
self.posts.append(post)
return post
def get_post_count(self):
return len(self.p…How to Implement Iterator Protocol on a Custom Class in Python
Create a custom iterable class by defining the __iter__ and __next__ methods, enabling use in for loops and list conversions.
class Countdown:
"""Iterator that counts down from start to 0."""
def __init__(self, start):
self.start = start
self.current = start
def __iter__(self):
return self
def __next__(self):
if self.current < 0:
raise StopIteration
value = self.current
…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.
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…Parse CSV Data with a Python Class
Encapsulate CSV file loading and column/row access methods in a reusable DataParser class for beginners.
class DataParser:
def __init__(self, file_path):
self.file_path = file_path
self.data = []
def load_data(self):
with open(self.file_path, 'r') as file:
for line in file:
row = line.strip().split(',')
self.data.append(row)
return self.…Python Factory Method: Create Shapes by Type String
A factory method that maps a type string to a concrete shape class and returns an instance, with runtime error handling.
class Shape:
def draw(self):
raise NotImplementedError
class Circle(Shape):
def draw(self):
return "Drawing a circle"
class Square(Shape):
def draw(self):
return "Drawing a square"
class Triangle(Shape):
def draw(self):
return "Drawing a triangle"
class ShapeFact…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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