proxy.py

from abc import ABC, abstractmethod

# Service interface
class Subject(ABC):
 @abstractmethod
 def request(self):
 pass

# ConcreteService
class RealSubject(Subject):
 def request(self):
 print("RealSubject: Handling request.")

# ProxyService
class Proxy(Subject):
 def __init__(self):
 self._real_subject = RealSubject() # ConcreteService

 def request(self):
 # Access control or additional logic can be added here
 print("Proxy: Checking access before handling request.")
 self._real_subject.request()

# Client code
def client_code(subject: Subject):
 subject.request()

# Usage
def main():
 real_subject = RealSubject()
 proxy = Proxy()

 print("Client: Directly interacting with the RealSubject:")
 client_code(real_subject)

 print("\nClient: Indirectly interacting with the Proxy:")
 client_code(proxy)

if __name__ == "__main__":
 main()

## Output
# Client: Directly interacting with the RealSubject:
# RealSubject: Handling request.

# Client: Indirectly interacting with the Proxy:
# Proxy: Checking access before handling request.
# RealSubject: Handling request.