PCAP Closures and Decorators 3

Question 1

What does `@property` allow you to do in a Python class?

Accepted Answer

Define a method that is accessed like an attribute, triggering computation on read

Answer

`@property` turns a method into a managed attribute getter; accessing `obj.value` silently calls the decorated method instead of returning a raw attribute.

Question 2

Which built-in decorator marks a method that receives the class object (not an instance) as its first implicit argument?

Accepted Answer

@classmethod

Answer

`@classmethod` methods receive `cls` as their first argument, giving them access to the class itself so they can create alternative constructors or access class-level state.

Question 3

What makes a `@staticmethod` different from a regular instance method?

Accepted Answer

It receives neither self nor cls and is essentially a plain function namespaced inside the class

Answer

A static method has no implicit first argument, so it has no access to the instance or the class; it is logically grouped inside the class purely for organizational purposes.

Question 4

What is memoization as used in closure-based and decorator-based Python patterns?

Accepted Answer

Caching a function's return values keyed by its arguments so repeated calls skip recomputation

Answer

Memoization stores previously computed results so that a function called with the same arguments again can return the cached result instantly instead of repeating the work.

Question 5

What does `@functools.lru_cache(maxsize=128)` do to the decorated function?

Accepted Answer

Automatically memoizes return values using a Least-Recently-Used cache limited to 128 entries

Answer

`lru_cache` wraps the function with an LRU cache; when the cache reaches `maxsize` entries, the least-recently-used entry is evicted to make room for a new one.

PCAP - Certified Associate in Python Programming Practice Test

PCAP - Certified Associate in Python Programming Practice Test

PCAP Closures and Decorators 3