What is Enum?
A built-in class for creating enumerated constants — named groups of related values that improve code readability.
Enums replace magic numbers and strings with meaningful names: class Color(Enum): RED = 1; GREEN = 2; BLUE = 3. Access via Color.RED, Color(1), or Color['RED']. Members are iterable and comparable.
Specialized enums include IntEnum (integer-compatible), StrEnum (Python 3.11+, string-compatible), Flag (combinable with bitwise operators), and auto() for automatic value assignment. Enums make code more readable and prevent invalid values.