Creating Variables

Learning Objectives Differentiate between local and global variable scope. Correctly apply type casting to convert variables between strings, integers, and floats. Define and use constants according to programming conventions. Utilize multiple assignment to initialize several variables in a single line of code. Apply standard naming conventions (like snake_case) for variable clarity and readability. Explain how variable scope can prevent or cause bugs in a program. Ever wonder how a game remembers your high score even after you finish a level, but forgets your temporary power-up? 🤔 It's all about where and how variables are created! In this lesson, we'll move beyond basic variable creation. You'll learn advanced techniques like controlling a variable's...

TermDefinitionExample Variable ScopeThe region of a program where a variable can be accessed. A variable created inside a function is 'local' to that function, while a variable created outside all functions is 'global'.In `def game_level(): score = 100`, the `score` variable is local and only exists inside the `game_level` function. Global VariableA variable declared in the main body of a program, outside of all functions. It can be accessed from anywhere in the code, including inside functions.`HIGH_SCORE = 9500` declared at the top of a file is a global variable. Local VariableA variable declared inside a function. It is only accessible from within that function and is destroyed when the function finishes executing.In `def calculate_tax(price): tax_amount = price * 0...

Type Casting Syntax `new_variable = new_type(old_variable)` To change a variable's type, use the target type's function (e.g., `int()`, `str()`, `float()`) and pass the variable you want to convert as an argument. Constant Naming Convention `CONSTANT_NAME = value` In Python, constants are not enforced by the language. We use all uppercase letters with underscores to signal to other developers that this variable's value is intended to remain fixed. Accessing Global Variables To modify a global variable from inside a function, you must use the `global` keyword: `global variable_name`. If you just read a global variable inside a function, you don't need the keyword. But if you want to change its value, you must first declare your intent with `global`...