- 01
When would you use a tuple instead of a list?
A tuple communicates a fixed collection and is immutable, while a list represents a collection expected to change. Tuples can also be hashable when all members are hashable, allowing their use as dictionary keys.
- 02
What is a Python generator and why is it useful?
Question codepythonsquares = [number * number for number in range(1_000_000)]A generator yields values lazily instead of building an entire collection in memory. It is useful for streams, large datasets, pipelines, and any workflow where values can be processed incrementally.
Answer codepythondef squares(limit: int): for number in range(limit): yield number * number for square in squares(1_000_000): process(square) - 03
How do decorators work in Python?
A decorator receives a callable and returns a replacement callable, usually adding behavior around the original function or class. Preserving metadata with functools.wraps is important when wrapping functions.
- 04
What does the GIL mean for Python concurrency?
In standard CPython, the Global Interpreter Lock allows one thread to execute Python bytecode at a time. Threads can still help with I/O-bound work, while CPU-bound workloads commonly use multiprocessing, native extensions, or distributed workers.
- 05
Why use type hints if Python is dynamically typed?
Type hints improve editor support, documentation, refactoring, and static analysis without changing Python into a statically typed runtime. They are most valuable when applied consistently at module and service boundaries.
- 06
How should dependencies be managed in a Python service?
Use an isolated environment, declare direct dependencies, and lock resolved versions for repeatable builds. Separate runtime and development tooling where useful, and keep dependency updates deliberate and tested.
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Python Interview Questions and Answers
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