To which group does the Proxy pattern belong and what is it used for?

The Proxy pattern belongs to the group of structural design patterns. Its main purpose is to provide a surrogate object that controls access to another object, intercepting calls and adding additional behavior if necessary.

Used for:

• Lazy initialization
• Access control
• Caching results
• Logging calls
• Remote access to objects

Example in Python:

class RealSubject:
    def request(self):
        print("Executing request")

class Proxy:
    def __init__(self):
        self.real_subject = RealSubject()

    def request(self):
        print("Proxy: checking access before call")
        self.real_subject.request()
        print("Proxy: additional behavior after call")

proxy = Proxy()
proxy.request()