Python Interview Questions
Learn Python structures, decorators, memory management, and practical application logic. Prepare with these 1 real-world questions covering beginner to advanced scenarios.
How do Decorators work in Python?
Simple Answer
A decorator is a function that takes another function and extends its behavior without modifying it explicitly. It allows you to wrap a function with additional logic, like checking if a user is logged in before letting them access a route.
Detailed Answer
Because Python functions are first-class citizens (they can be passed as arguments), a decorator takes a function as an argument, defines a wrapper function inside it that executes the additional code (before or after the original function), and then returns the wrapper. We use the `@decorator_name` syntax above a function as syntactic sugar for `func = decorator_name(func)`.
Interview Tip
If asked to write one on a whiteboard, don't forget to use `functools.wraps` inside your decorator to preserve the original function's metadata (like its name and docstring).
Common Mistake
Forgetting to return the inner wrapper function at the end of the decorator.
Real World Example
In Flask or FastAPI, you use `@app.route('/home')` to attach routing logic to a function. Or you might use `@login_required` to check authentication before a user can view a dashboard function.
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Question 1 of 1How do Decorators work in Python?
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