The Black Box Mental Model
A function is a magical black box. You feed in inputs (arguments), it performs internal transformations in its own private stack frame, and it ejects a single output (return value) without polluting the outside global scope.
Anatomy of a Clean Python Function
def calculate_tax(subtotal: float, rate: float = 0.08) -> float:
"""Calculate total tax amount given subtotal and rate."""
tax_amount = subtotal * rate
return round(tax_amount, 2)
Quick Summary
- Functions encapsulate isolated logic with clear inputs and return values.
- Next, we explore Python's built-in Data Structures (Lists, Dicts, Sets, Tuples).