Python Singleton.get_instance примеры использования

Пример #1

from Singleton import Singleton
from PricingRule import PricingRule
from Checkout import Checkout

if __name__ == '__main__':
    singleton = Singleton.get_instance()
    co = Checkout(PricingRule())
    co.scan(singleton.productManager.get_product('mbp'))
    co.scan(singleton.productManager.get_product('vga'))
    co.scan(singleton.productManager.get_product('vga'))
    print(co.total())