{
    "cells": [
        {
            "cell_type": "markdown",
            "id": "4217c5b9",
            "metadata": {},
            "source": [
                "# Python Basics - 11. Scope, Closures, and Decorators\n",
                "\n",
                "This notebook explains variable scope (LEGB), closures, and decorators. These topics are key to understanding how Python functions behave in real projects."
            ]
        },
        {
            "cell_type": "markdown",
            "id": "01488228",
            "metadata": {
                "language": "markdown"
            },
            "source": [
                "## Download Notebook\n",
                "\n",
                "{download}`Download this notebook <11_scope_closures_and_decorators.ipynb>`\n"
            ]
        },
        {
            "cell_type": "markdown",
            "id": "eee44670",
            "metadata": {},
            "source": [
                "## 1. LEGB Scope Rule\n",
                "\n",
                "Python resolves names in this order: Local, Enclosing, Global, Built-in."
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "id": "8dda99f4",
            "metadata": {},
            "outputs": [],
            "source": [
                "message = \"global\"\n",
                "\n",
                "def outer():\n",
                "    message = \"enclosing\"\n",
                "    def inner():\n",
                "        message = \"local\"\n",
                "        print(f\"Inner sees: {message}\")\n",
                "    inner()\n",
                "    print(f\"Outer sees: {message}\")\n",
                "\n",
                "outer()\n",
                "print(f\"Global sees: {message}\")"
            ]
        },
        {
            "cell_type": "markdown",
            "id": "8dff8819",
            "metadata": {},
            "source": [
                "## 2. Closures\n",
                "\n",
                "A closure is an inner function that remembers values from its enclosing scope even after the outer function returns."
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "id": "5917e504",
            "metadata": {},
            "outputs": [],
            "source": [
                "def make_multiplier(factor):\n",
                "    def multiply(x):\n",
                "        return x * factor\n",
                "    return multiply\n",
                "\n",
                "double = make_multiplier(2)\n",
                "triple = make_multiplier(3)\n",
                "print(double(10), triple(10))"
            ]
        },
        {
            "cell_type": "markdown",
            "id": "a29340e7",
            "metadata": {},
            "source": [
                "## 3. Decorators\n",
                "\n",
                "A decorator wraps a function to add behavior before/after execution without changing the original function body."
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "id": "13ea09d9",
            "metadata": {},
            "outputs": [],
            "source": [
                "def log_call(func):\n",
                "    def wrapper(*args, **kwargs):\n",
                "        print(f\"Calling {func.__name__} with args={args}, kwargs={kwargs}\")\n",
                "        result = func(*args, **kwargs)\n",
                "        print(f\"{func.__name__} returned {result}\")\n",
                "        return result\n",
                "    return wrapper\n",
                "\n",
                "@log_call\n",
                "def add(a, b):\n",
                "    return a + b\n",
                "\n",
                "add(5, 7)"
            ]
        }
    ],
    "metadata": {
        "language_info": {
            "name": "python"
        }
    },
    "nbformat": 4,
    "nbformat_minor": 5
}