What is Python's enum module?
Why Interviewers Ask This
This question targets practical, hands-on experience with Python. Interviewers want to see if you've worked with these concepts in real projects, not just read about them. Strong answers include concrete examples.
Answer
The enum module (Python 3.4+) provides a formal way to define named constants. from enum import Enum, auto; class Color(Enum): RED = 1; GREEN = 2; BLUE = 3. Access: Color.RED (member), Color.RED.value (1), Color.RED.name ("RED"). Iterate: list(Color). Check membership: isinstance(Color.RED, Color). auto() assigns sequential values automatically. IntEnum: behaves like int in comparisons. Flag/IntFlag: for bitwise operations (permissions): class Perm(Flag): READ = auto(); WRITE = auto(); EXECUTE = auto(); RW = READ | WRITE. StrEnum (Python 3.11+): string-valued enum. Enums are iterable, comparable, and hashable — use them as dict keys. They replace magic number/string constants with readable, type-safe values. Enums work well with match/case (Python 3.10+) for exhaustive pattern matching.
Common Mistake
Many candidates answer correctly but can't explain the 'why'. Always be prepared to justify your answer with a concrete example or use case from your Python experience.