ExamAdept

Which built-in decorator is used to enforce that a function is only called once?

A:

@staticmethod

B:

@functools.lru_cache

C:

@functools.singledispatch

D:

@functools.singledispatchmethod

Answer: C

The @functools.singledispatch decorator is used to define a single-dispatch generic function, ensuring that the function is only called once for a particular type.

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What does the @wraps decorator do?

A:

Marks a method as a static method

B:

Provides a way to document and maintain the original function's metadata

C:

Converts a method to a class method

D:

Indicates a method is an instance method

Answer: B

The @wraps decorator is used to preserve the original metadata of a function, including its name, docstring, and other attributes, when creating a wrapper or decorator.

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Which of the following decorators is used to cache the result of a function to improve performance?

A:

@staticmethod

B:

@property

C:

@functools.lru_cache

D:

@classmethod

Answer: C

The @functools.lru_cache decorator is used to cache the result of a function with the least recently used (LRU) strategy, improving the performance by avoiding redundant calculations.

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How does the @property decorator differ from regular methods in a Python class?

A:

It defines a read-only property without a setter method

B:

It marks a method as a class method

C:

It is used to create private methods

D:

It enables dynamic method invocation

Answer: A

The @property decorator is used to define read-only properties in a class. It allows you to access a method as an attribute without the need for explicit getter methods. However, it doesn't provide a setter method, making the property read-only.

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Questions for: Decorators