proxy.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import time


class SalesManager:

    def work(self):
        print("Sales Manager working...")

    def talk(self):
        print("Sales Manager ready to talk")


class Proxy:

    def __init__(self):
        self.busy = 'No'
        self.sales = None

    def work(self):
        print("Proxy checking for Sales Manager availability")
        if self.busy == 'No':
            self.sales = SalesManager()
            time.sleep(2)
            self.sales.talk()
        else:
            time.sleep(2)
            print("Sales Manager is busy")


if __name__ == '__main__':
    p = Proxy()
    p.work()
    p.busy = 'Yes'
    p.work()

### OUTPUT ###
# Proxy checking for Sales Manager availability
# Sales Manager ready to talk
# Proxy checking for Sales Manager availability
# Sales Manager is busy