Technical

The Most Important Object Oriented Programming Concept in Python and How It Applies To Web Development

Matthew Fieldhouse

Matthew Fieldhouse

— 1 min read

Okay, imagine you're playing with LEGO blocks! Object-Oriented Programming (OOP) in Python is like building with LEGO blocks, where each block is special and can do certain things.

The most important concept: Classes and Objects

  • Class: A class is like a blueprint for a LEGO block. It tells you what the block will look like and what it can do.
  • Object: An object is the actual LEGO block built from the blueprint. You can create many blocks (objects) from one blueprint (class).

Example:

class Stock:
    def __init__(self, symbol, five_year_high, current_price):
        self.symbol = symbol
        self.five_year_high = five_year_high
        self.current_price = current_price
        self.thresholds = [{"percentage": p, "breached": False} for p in [20, 30, 50, 70]]

    def check_thresholds(self):
        for threshold in self.thresholds:
            threshold_price = self.five_year_high * (1 - threshold["percentage"] / 100)
            if self.current_price <= threshold_price and not threshold["breached"]:
                print(f"Threshold breached for {self.symbol}!")
                threshold["breached"] = True

ticker_db = {
    "AAPL": Stock("AAPL", 150, 120)
}

How it helps in Web Development:

When you build websites, each part of the site can be its own LEGO block (class)!

Example: Making a Web Store with Cars

  • Class Car: Describes the cars for sale.
  • Class User: Describes the people using the website.
  • Class ShoppingCart: Describes what people add to buy.

Imagine a user adds a car to their shopping cart:

class ShoppingCart:
    def __init__(self):
        self.items = []

    def add_item(self, item):
        self.items.append(item)
        print(f"{item.model} added to cart!")

cart = ShoppingCart()
cart.add_item(car1)  # red Toyota added to cart!

Why It's Cool for Web Development:

  1. Reusable: You can create many cars or users from the same blueprint (class).
  2. Organized: Keeps everything neat and separate (cars, users, shopping carts).
  3. Scalable: If you want to add new features (like a discount), you just update the class!

Web frameworks like Django and Flask use OOP to build web apps, treating things like pages, users, and products as objects! It's like building your entire website with LEGO blocks.

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